When I was doing research for my Lanthorn interpreter to support native disk formats and the original color schemes I took a bunch of screenshots from various emulators (and borrowed a few screenshots from the web or YouTube walkthroughs). The screenshots are all here if you need references for various platforms: lanthorn/machine-screenshots at main · sharkusk/lanthorn · GitHub
one note, the C64 colors looked different depending upon the release (see the screenshots). And C128 in 80 col mode was also unique.