Sorry, but I've never really understood asking what other people choose for their font colors during the day. Fire the skin up in the car, go to the color chooser screen, and try a few. Just pick a color, choose change font, and look at the buttons on the bottom. If its hard to read, rinse and repeat That is the best way to see how it looks, and choose a color that is easy to read, and matches your car if possible.
I know, many will say, well my PC isn't in the car yet. Well get it all built & installed when you are ready, and then follow the above procedure
The main reason I say this, is over the past week, when this question has been asked in different posts. I have seen responses for orange, yellow, white, green, light blue, light red, and an array of other colors. well this covers just about everything, so it is really of no help. No one is going to be able to tell anyone exactly what color to use, and everyone be happy with it. It basically just comes down to the individual's taste and readability.
I did the best I could to prepare for this, making text area's and buttons darker than the background color, still allowing for transparency. This gives as much contrast as possible, well trying to maintain a bit of transparency for the buttons and text area's.