Illustrator Changes Colours?

Question

I am designing a swing tag for a client. I have designed it in Illustrator, for print, in CMYK profile.

One rectangle object in the design needs the fill colour to be a web safe blue #0099ff / C70 M34 Y0 K0

but when I click off the object, then click back on it and check the colour it has changed to #3399cc / C73 M26 Y5 K0

Can any body tell me why it is changing the colour and how I can make sure the colour I want, stays as I want it?

Thank you in advance!

Answer 1

Simple answer is that you can't use that color in CMYK

http://designmodo.com/obtain-right-color-illustrator/