I have a brochure which I'm trying to print it has a few shades of purple and grey.
At one printing center, Digital Printing, the colors came out completely wrong as blues instead of purples and very dark gray. I tried a different center and the purple came out kinda pinkish but the gray comes out as yellow.
Originally the file was CMYK but I changed it to RGB later and saved it as PDF which was later used for printing.
Edit: I don't really know the type of the printer but maybe I'll try saving it as CMYK and print it again and see how it turns out