Adjusting Height of Panel Columns using CSS
to achieve this you need make use of CSS pseudo selectors and apply them in the correct element, a good approach can be this:

.panel-2col-bricks &gt; .panel-panel:nth-child(2) .center-wrapper .panel-col-first,
.panel-2col-bricks &gt; .panel-panel:nth-child(2) .center-wrapper .panel-col-last


You can see this in action in the link below:
https://codepen.io/anon/pen/xBZGGb