Search icon color and center menu

Hello, I have been trying to find the correct code to change the color of the search icon and I have tried just about everything and it has not worked. Is anyone able to assist? I found the right CSS to change the size of the search icon but, the color will not change.

Also, I have not been able to center the menu. I’d like it to stay as header layout 2, but the codes that I’ve tried to center the menu have not worked. Please help!

Thanks!