Android :: Allow User To Choose A Color Between 4 In Droid?

I'm making an Android App, and i need to put a control that let user choose between 4 different colors. I want to do this with something like radio buttons: the problem is that radiobuttons are round...

is there a way to set them looks like square/rect buttons, and assign a color to their inside rect area ?

If not, how can i achieve that choose for the user ?

I need this because i'm making a Todo/Task android application, and i need the user to choose the priority of a task, between for priority level that are rapresented with a color. So i think to do that by showing 4 buttons, each with a different color associated, and a text inside ("0", "1", "2", "3")