To understand this we have a lot to consider from the host PC to how color printing works.
My background involves apps that dealt with translating color from a fixed RGB level to a color on the LCD. This turned out to take a lot of time in the CPU as we calculated the closest color we had in the LCD color palette.
-> There's also so very old issues with XP and IDE DMA but your post seems to omit all the PC details so I can't guess if that's in play here.
At least it works. Your post seems to just note it has to think about it.
Bob
Hello, my computer seems like its having hard time sending over documents with color in them. If I print just a normal word document black and white it will start printing instantly. On the other hand when I try to print and excel file are something with color the print manager shows it sticking at like 58kb/128kb and sometimes it will be at 84kb/128kb and go back down to 58kb. So to me it just seems like its having a hard time processing the color? Also other computers are have ZERO issues printing color on the same printer.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic