How can I make sure my blues do not come out purple?
When using a blue in your design, always make sure to leave at least a 30% difference in your Cyan and Magenta values.
100% C 100% M 0% Y 0% K
Blue is close to purple in the CMYK spectrum. Remember, use a low amount of magenta whenever using high amounts of cyan to avoid purple.
EXAMPLE: C-100 M-70 Y-0 K-0