Hi Marcelo11756
You can control the button padding, color and shape through the Display screen found under Customize > Display.
What you might find more useful if you aren't doing this already is setting the buttons to display across the width of two or more cells. You can do this by following the steps below:
Step 1 - Choose the screen you wish to customize and edit it. Please note that you can't undo changes so it is good to get into the habit of taking a copy of the screen before making changes. Let's say you have 3 columns at the moment and the buttons are in the third column.
Step 2 - Drag all of the buttons into the second column
Step 3 - Click the little two way arrow button at the top of one of the button objects in the cell. This will expand the cell content across the width of two cells.
Step 4 - It should end up looking something like this.
I hope that helps. Let me know if you have any further questions.
Jeff