For your casual wardrobe, try to avoid the traditional "khaki" color, which can look, what I call, a little too suburban. Instead, opt for gray (light or dark), blue (a bright blue is great), dark jeans and navy.
For dress trousers and suits, stick with a medium to dark gray and navy. A black suit will never go out of style, but a blue suit is a bit more modern and looks fabulous with white, red, yellow, orange, lavender... you name it, you can wear it with navy!
I've created a list of wardrobe basics for men. You can download a free copy here: https://www.noellecellinistyle.com/p/home/ While black is a wardrobe staple, navy is just as versatile and much more flattering (it isn't as harsh as black and I haven't met a man who doesn't look good in navy!