Go to form template (components\com_fabrik\views\form\tmpl\bootstrap) and replace code below inside default_actions.php
<?php
/**
 * Bootstrap Form Template - Actions
 *
 * @package     Joomla
 * @subpackage  Fabrik
 * @copyright   Copyright (C) 2005-2016  Media A-Team, Inc. - All rights reserved.
 * @license     GNU/GPL http://www.gnu.org/copyleft/gpl.html
 * @since       3.1
 */

// No direct access
defined('_JEXEC') or die('Restricted access');

$form = $this->form;
if ($this->hasActions) : ?>
<div style="text-align: center;" class="fabrikActions form-actions">
	<div id="button">
		<?php
			echo $form->prevButton;
			echo $form->submitButton;
			echo $form->applyButton;
			echo $form->gobackButton;
			echo $form->resetButton;
			echo $form->deleteButton;
			echo $form->nextButton;
			echo $form->copyButton;
			echo $form->clearMultipageSessionButton;
		?>
	</div>
</div>
<?php endif; ?>

<style type="text/css">
.fabrikActions .btn {
	-moz-box-shadow:inset 0px 1px 0px 0px #ffffff !important;
	-webkit-box-shadow:inset 0px 1px 0px 0px #ffffff !important;
	box-shadow:inset 0px 1px 0px 0px #ffffff !important;
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #ededed), color-stop(1, #dfdfdf)) !important;
	background:-moz-linear-gradient(top, #ededed 5%, #dfdfdf 100%) !important;
	background:-webkit-linear-gradient(top, #ededed 5%, #dfdfdf 100%) !important;
	background:-o-linear-gradient(top, #ededed 5%, #dfdfdf 100%) !important;
	background:-ms-linear-gradient(top, #ededed 5%, #dfdfdf 100%) !important;
	background:linear-gradient(to bottom, #ededed 5%, #dfdfdf 100%) !important;
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#ededed', endColorstr='#dfdfdf',GradientType=0) !important;
	background-color:#ededed !important;
	-moz-border-radius:6px !important;
	-webkit-border-radius:6px !important;
	border-radius:3px !important;
	border:1px solid #dcdcdc !important;
	display:inline-block !important;
	cursor:pointer !important;
	color:#ffffff !important;
	font-family:Arial !important;
	font-size:12px !important;
	font-weight:bold !important;
	padding:6px 24px !important;
	text-decoration:none !important;
	text-shadow:0px 1px 0px #ffffff !important;
	text-transform: none !important;
	width: auto !important; 
	min-width: 90px !important;
	float: none !important;
}
.fabrikActions .btn:hover {
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #dfdfdf), color-stop(1, #ededed)) !important;
	background:-moz-linear-gradient(top, #dfdfdf 5%, #ededed 100%) !important;
	background:-webkit-linear-gradient(top, #dfdfdf 5%, #ededed 100%) !important;
	background:-o-linear-gradient(top, #dfdfdf 5%, #ededed 100%) !important;
	background:-ms-linear-gradient(top, #dfdfdf 5%, #ededed 100%) !important;
	background:linear-gradient(to bottom, #dfdfdf 5%, #ededed 100%) !important;
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#dfdfdf', endColorstr='#ededed',GradientType=0) !important;
	background-color:#dfdfdf !important;
}
.fabrikActions .btn[name=Submit] {
	-moz-box-shadow:inset 0px 1px 0px 0px #97c4fe !important;
	-webkit-box-shadow:inset 0px 1px 0px 0px #97c4fe !important;
	box-shadow:inset 0px 1px 0px 0px #97c4fe !important;
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #3d94f6), color-stop(1, #1e62d0)) !important;
	background:-moz-linear-gradient(top, #3d94f6 5%, #1e62d0 100%) !important;
	background:-webkit-linear-gradient(top, #3d94f6 5%, #1e62d0 100%) !important;
	background:-o-linear-gradient(top, #3d94f6 5%, #1e62d0 100%) !important;
	background:-ms-linear-gradient(top, #3d94f6 5%, #1e62d0 100%) !important;
	background:linear-gradient(to bottom, #3d94f6 5%, #1e62d0 100%) !important;
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#3d94f6', endColorstr='#1e62d0',GradientType=0) !important;
	background-color:#3d94f6 !important;
	border:1px solid #337fed !important;
	text-shadow:0px 1px 0px #1570cd !important;
}
.fabrikActions .btn[name=Submit]:hover {
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #1e62d0), color-stop(1, #3d94f6)) !important;
	background:-moz-linear-gradient(top, #1e62d0 5%, #3d94f6 100%) !important;
	background:-webkit-linear-gradient(top, #1e62d0 5%, #3d94f6 100%) !important;
	background:-o-linear-gradient(top, #1e62d0 5%, #3d94f6 100%) !important;
	background:-ms-linear-gradient(top, #1e62d0 5%, #3d94f6 100%) !important;
	background:linear-gradient(to bottom, #1e62d0 5%, #3d94f6 100%) !important;
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#1e62d0', endColorstr='#3d94f6',GradientType=0) !important;
	background-color:#1e62d0 !important;
}
.fabrikActions .btn[name=apply] {
	-moz-box-shadow:inset 0px 1px 0px 0px #fbafe3 !important;
	-webkit-box-shadow:inset 0px 1px 0px 0px #fbafe3 !important;
	box-shadow:inset 0px 1px 0px 0px #fbafe3 !important;
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #ff5bb0), color-stop(1, #ef027d)) !important;
	background:-moz-linear-gradient(top, #ff5bb0 5%, #ef027d 100%) !important;
	background:-webkit-linear-gradient(top, #ff5bb0 5%, #ef027d 100%) !important;
	background:-o-linear-gradient(top, #ff5bb0 5%, #ef027d 100%) !important;
	background:-ms-linear-gradient(top, #ff5bb0 5%, #ef027d 100%) !important;
	background:linear-gradient(to bottom, #ff5bb0 5%, #ef027d 100%) !important;
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#ff5bb0', endColorstr='#ef027d',GradientType=0) !important;
	background-color:#ff5bb0 !important;
	border:1px solid #ee1eb5 !important;
	text-shadow:0px 1px 0px #c70067 !important;
}
.fabrikActions .btn[name=apply]:hover {
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #ef027d), color-stop(1, #ff5bb0)) !important;
	background:-moz-linear-gradient(top, #ef027d 5%, #ff5bb0 100%) !important;
	background:-webkit-linear-gradient(top, #ef027d 5%, #ff5bb0 100%) !important;
	background:-o-linear-gradient(top, #ef027d 5%, #ff5bb0 100%) !important;
	background:-ms-linear-gradient(top, #ef027d 5%, #ff5bb0 100%) !important;
	background:linear-gradient(to bottom, #ef027d 5%, #ff5bb0 100%) !important;
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#ef027d', endColorstr='#ff5bb0',GradientType=0) !important;
	background-color:#ef027d !important;
}
.fabrikActions .btn[name=Goback] {
	-moz-box-shadow:inset 0px 1px 0px 0px #d9fbbe !important;
	-webkit-box-shadow:inset 0px 1px 0px 0px #d9fbbe !important;
	box-shadow:inset 0px 1px 0px 0px #d9fbbe !important;
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #b8e356), color-stop(1, #a5cc52)) !important;
	background:-moz-linear-gradient(top, #b8e356 5%, #a5cc52 100%) !important;
	background:-webkit-linear-gradient(top, #b8e356 5%, #a5cc52 100%) !important;
	background:-o-linear-gradient(top, #b8e356 5%, #a5cc52 100%) !important;
	background:-ms-linear-gradient(top, #b8e356 5%, #a5cc52 100%) !important;
	background:linear-gradient(to bottom, #b8e356 5%, #a5cc52 100%) !important;
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#b8e356', endColorstr='#a5cc52',GradientType=0) !important;
	background-color:#b8e356 !important;
	border:1px solid #83c41a !important;
	text-shadow:0px 1px 0px #86ae47 !important;
}
.fabrikActions .btn[name=Goback]:hover {
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #a5cc52), color-stop(1, #b8e356)) !important;
	background:-moz-linear-gradient(top, #a5cc52 5%, #b8e356 100%) !important;
	background:-webkit-linear-gradient(top, #a5cc52 5%, #b8e356 100%) !important;
	background:-o-linear-gradient(top, #a5cc52 5%, #b8e356 100%) !important;
	background:-ms-linear-gradient(top, #a5cc52 5%, #b8e356 100%) !important;
	background:linear-gradient(to bottom, #a5cc52 5%, #b8e356 100%) !important;
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#a5cc52', endColorstr='#b8e356',GradientType=0) !important;
	background-color:#a5cc52 !important;
}
.fabrikActions .btn[name=Reset] {
	-moz-box-shadow:inset 0px 1px 0px 0px #e184f3 !important;
	-webkit-box-shadow:inset 0px 1px 0px 0px #e184f3 !important;
	box-shadow:inset 0px 1px 0px 0px #e184f3 !important;
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #c123de), color-stop(1, #a20dbd)) !important;
	background:-moz-linear-gradient(top, #c123de 5%, #a20dbd 100%) !important;
	background:-webkit-linear-gradient(top, #c123de 5%, #a20dbd 100%) !important;
	background:-o-linear-gradient(top, #c123de 5%, #a20dbd 100%) !important;
	background:-ms-linear-gradient(top, #c123de 5%, #a20dbd 100%) !important;
	background:linear-gradient(to bottom, #c123de 5%, #a20dbd 100%) !important;
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#c123de', endColorstr='#a20dbd',GradientType=0) !important;
	background-color:#c123de !important;
	border:1px solid #a511c0 !important;
	text-shadow:0px 1px 0px #9b14b3 !important;
}
.fabrikActions .btn[name=Reset]:hover {
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #a20dbd), color-stop(1, #c123de)) !important;
	background:-moz-linear-gradient(top, #a20dbd 5%, #c123de 100%) !important;
	background:-webkit-linear-gradient(top, #a20dbd 5%, #c123de 100%) !important;
	background:-o-linear-gradient(top, #a20dbd 5%, #c123de 100%) !important;
	background:-ms-linear-gradient(top, #a20dbd 5%, #c123de 100%) !important;
	background:linear-gradient(to bottom, #a20dbd 5%, #c123de 100%) !important;
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#a20dbd', endColorstr='#c123de',GradientType=0) !important;
	background-color:#a20dbd !important;
}
.fabrikActions .btn[name=fabrikPagePrevious], .fabrikActions .btn[name=fabrikPageNext] {
	-moz-box-shadow:inset 0px 1px 0px 0px #9fb4f2 !important;
	-webkit-box-shadow:inset 0px 1px 0px 0px #9fb4f2 !important;
	box-shadow:inset 0px 1px 0px 0px #9fb4f2 !important;
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #7892c2), color-stop(1, #476e9e)) !important;
	background:-moz-linear-gradient(top, #7892c2 5%, #476e9e 100%) !important;
	background:-webkit-linear-gradient(top, #7892c2 5%, #476e9e 100%) !important;
	background:-o-linear-gradient(top, #7892c2 5%, #476e9e 100%) !important;
	background:-ms-linear-gradient(top, #7892c2 5%, #476e9e 100%) !important;
	background:linear-gradient(to bottom, #7892c2 5%, #476e9e 100%) !important;
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#7892c2', endColorstr='#476e9e',GradientType=0) !important;
	background-color:#7892c2 !important;
	border:1px solid #4e6096 !important;
	text-shadow:0px 1px 0px #949494 !important;
}
.fabrikActions .btn[name=fabrikPagePrevious]:hover, .fabrikActions .btn[name=fabrikPageNext]:hover {
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #476e9e), color-stop(1, #7892c2)) !important;
	background:-moz-linear-gradient(top, #476e9e 5%, #7892c2 100%) !important;
	background:-webkit-linear-gradient(top, #476e9e 5%, #7892c2 100%) !important;
	background:-o-linear-gradient(top, #476e9e 5%, #7892c2 100%) !important;
	background:-ms-linear-gradient(top, #476e9e 5%, #7892c2 100%) !important;
	background:linear-gradient(to bottom, #476e9e 5%, #7892c2 100%) !important;
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#476e9e', endColorstr='#7892c2',GradientType=0) !important;
	background-color:#476e9e !important;
}
.fabrikActions .btn[name=delete] {
	-moz-box-shadow:inset 0px 1px 0px 0px #f5978e !important;
	-webkit-box-shadow:inset 0px 1px 0px 0px #f5978e !important;
	box-shadow:inset 0px 1px 0px 0px #f5978e !important;
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #f24537), color-stop(1, #c62d1f)) !important;
	background:-moz-linear-gradient(top, #f24537 5%, #c62d1f 100%) !important;
	background:-webkit-linear-gradient(top, #f24537 5%, #c62d1f 100%) !important;
	background:-o-linear-gradient(top, #f24537 5%, #c62d1f 100%) !important;
	background:-ms-linear-gradient(top, #f24537 5%, #c62d1f 100%) !important;
	background:linear-gradient(to bottom, #f24537 5%, #c62d1f 100%) !important;
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#f24537', endColorstr='#c62d1f',GradientType=0) !important;
	background-color:#f24537 !important;
	border:1px solid #d02718 !important;
	text-shadow:0px 1px 0px #810e05 !important;
}
.fabrikActions .btn[name=delete]:hover {
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #c62d1f), color-stop(1, #f24537)) !important;
	background:-moz-linear-gradient(top, #c62d1f 5%, #f24537 100%) !important;
	background:-webkit-linear-gradient(top, #c62d1f 5%, #f24537 100%) !important;
	background:-o-linear-gradient(top, #c62d1f 5%, #f24537 100%) !important;
	background:-ms-linear-gradient(top, #c62d1f 5%, #f24537 100%) !important;
	background:linear-gradient(to bottom, #c62d1f 5%, #f24537 100%) !important;
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#c62d1f', endColorstr='#f24537',GradientType=0) !important;
	background-color:#c62d1f !important;
}
.fabrikActions .btn[name=Copy] {
	-moz-box-shadow:inset 0px 1px 0px 0px #fce2c1 !important;
	-webkit-box-shadow:inset 0px 1px 0px 0px #fce2c1 !important;
	box-shadow:inset 0px 1px 0px 0px #fce2c1 !important;
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #ffc477), color-stop(1, #fb9e25)) !important;
	background:-moz-linear-gradient(top, #ffc477 5%, #fb9e25 100%) !important;
	background:-webkit-linear-gradient(top, #ffc477 5%, #fb9e25 100%) !important;
	background:-o-linear-gradient(top, #ffc477 5%, #fb9e25 100%) !important;
	background:-ms-linear-gradient(top, #ffc477 5%, #fb9e25 100%) !important;
	background:linear-gradient(to bottom, #ffc477 5%, #fb9e25 100%) !important;
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#ffc477', endColorstr='#fb9e25',GradientType=0) !important;
	background-color:#ffc477 !important;
	border:1px solid #eeb44f !important;
	text-shadow:0px 1px 0px #cc9f52 !important;
}
.fabrikActions .btn[name=Copy]:hover {
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #fb9e25), color-stop(1, #ffc477)) !important;
	background:-moz-linear-gradient(top, #fb9e25 5%, #ffc477 100%) !important;
	background:-webkit-linear-gradient(top, #fb9e25 5%, #ffc477 100%) !important;
	background:-o-linear-gradient(top, #fb9e25 5%, #ffc477 100%) !important;
	background:-ms-linear-gradient(top, #fb9e25 5%, #ffc477 100%) !important;
	background:linear-gradient(to bottom, #fb9e25 5%, #ffc477 100%) !important;
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#fb9e25', endColorstr='#ffc477',GradientType=0) !important;
	background-color:#fb9e25 !important;
}
.form-actions {
	background-color: lavender !important;
}
.fabrikActions .btn > i {
	display: none !important;
}
</style>