No.
If you had tan pants and a blue shirt, then yes.
White or cream or red
Probably white or any color
Brutus wears blue pants and a black shirt in Popeye.
Yes, but it would not be a good combo unless the blazer and the khakis were a very, very close match. If you have a choice, opt for blue twills or even (blue) denim for the pants.
In the Marvel Cinematic Universe, Thor typically wears a blue shirt and red cape with black pants.
Black, looks very nice with EVERYTHING. And Maybe a navy blue color for your pants, most pants go with blue, unless your the type to wear colored jeans, then be careful what you pick out. But anyway, if you need something to go with blue stay in the white, black, bluish, grey area if their pants. Hope this helps.
Yes.
why couldn't you?
red pants
They don't technically match, but I think they coordinate (meaning they go together). If the pants are a solid color, then you can definitely wear a striped shirt with them, and navy is a color that goes with most everything. You should be good!