The colors you see on computer are not the real one as monitor screen makes color look different. Besides,colors can be affected by printing machines,ink,temperature etc. So RGB or CMYK value are seldom used for color matching since final one will probably be different from what you see on computer.
For solid colors such as purely red, purely green etc, PMS code in paper edition should be offered for printing.
For Gradient colors, it can only be printed directly.
Printing quality depends on files provided for printing. Any file can be printed, but vague image must have bad printing effect.
Vector Image is preferred for printing.
High Resolution Image 300dpi above or image which is still clear enough when zoomed up to cover the product size can also be used for printing.
For text printing, text content and text font can be offered for printing.