My two favorite colors are the deep maroon and the deep purple. I usually have white, gray, or black rails with the same for supports. If the coaster and theming warrant, I'll change these. (for instance, my Fueding Families inverts are both variants of brown, winding through a hick village.) I try to make various designs. I enjoy all silver occasionally, and sometimes black and red, silver with red rails, etc. One really cool scheme I did was a racing woodie called "Racing Cheetahs." It was black supports with orange track, black rails, alternating with black track, orange rails, so it looked like a cheetah. It was cool. I also use the bright blue, sometimes in conjunction with green. I also like purple and gold, orange and silver, etc.
Jman