Setting tab order and removing outlines in graphics

I have a text entry form with graphical buttons for OK and Cancel. When I hit the Tab key to move to the next text field, instead of going to the next text field, it tabs to one of the buttons. Is there a way to set the tabbing order so that this doesn’t happen?

Another issue with this is that when the user tabs to the buttons, a yellow outline appears. I would like to, if it’s possible, either change the color of this outline or make it so that it doesn’t display an outline at all. Can I do this? If so, how?

Chris