Serious Sci Fi™ always assumes that alien ships, weapons, uniforms, etc., will be in Serious Colours™ - black/white/grey/dark red/etc. 

but like. what makes a colour Serious is totally culturally/environmentally defined.

what i’m saying is if you don’t have at least one alien race with terrifying badasses who dress entirely in pastel pinks and yellows you’re a goddamn coward.