I have never been able to answer this question. I have no favorite, catch-all, 100% best for everything color.
I’m finding more and more that I like the colors of the ninja turtles, though. Red, blue, purple, orange, and green… I think TMNT has influenced me even more than I thought!
If I had to pick 1 color to draw in for the rest of my life, though, I would use blue.