Depends on where you are fishing, river or lake, water conditions, weather conditions. One of the biggest rainbows I ever caught was right here in the ozarks while fishing for brown bass. I was bouncing a brown 1/8 lead head of the bottom of a small river to imitate a small crayfish. Instead of hooking a 1 lb brown bass, I hooked into a 6 lb 'bow. On 4 lb test line.
In an earlier post I stated HAVE AN ASSORTMENT. Different situations call for different weights of jigs and colors.
If you present your jig in a manner that imitates something the fish are eating, you will catch fish. You can also provoke a strike by using a bright color.