Expert: Amy - 10/7/2006

Question
I am trying to get a true blue and I choose a color combo of R:0 G:0 B:255 and it is the blue that I want. Illustrator then changes it automatically to a pastel blue. How do I get the actual color that I want?

Answer
Hi Erinne,

You are probably working in CMYK mode.  Look under File > Document Color Mode and check.

If you are creating graphics for the web, RGB mode is what you want. You'll get your bright blue then.

If you are creating a file to be printed at a print shop (traditional ink on paper), you must use CMYK workspaces and colors.

RGB is light/pixels on a screen - anything is possible. Even pure blue, since colors on the screen are made from red, green and blue inks.

CMYK is 4 inks that are mixed to create different colors. Not everything is possible. You are limited by the chemicals in the ink on your white paper. Not all RGB colors can be reproduced in CMYK. Illustrator automatically changes those colors to the closest color it can give you. That's why your bright blue is changing to a dull blue. That blue is "out of gamut" for CMYK inks.

When you convert a graphic from RGB to CMYK, some of your RGB colors won't be able to be achieved with CMYK inks. Illustrator puts a little yellow gamut warning symbol in the Color window when this is the case.  Greens are notoriously hard. You have to pick colors that come close to what you want and sometimes make some sacrifices.

Designers use tools like the Pantone process color guide to make sure they are choosing the right color for the job.

I hope this helped!

Amy