So you are programmer and not designer, but need to highlight something by using different colors? Create scheme, graph or some kind of drawing? Please don't use bold default colors like RED
#00FF00 and BLUE
#0000FF, or your creation will look like something from nineties.
Just go to COLOURlovers Top where people with taste and free time created and evaluated color palettes, that just look nice. If you need more colors use Adobe Color wheel to find colors that match. Its quick and simple, but your work will instantly look stylish and professional.