It's quite often said that one shouldn't use garish colours(100% Cyan or 100% Magenta) for offset printing. You may feel like breaking the norm and but you might want to listen to this because unfortunately, it is right. Because if you use them, the design might look great on the monitor but the print result will be poor. If you still want to use those colours, you might have to add a bit of other colours as well, 5-20% or use some other texture. I, personally, love to use garish colours.
Now let me relate the sad result of my little experiment. Death at Intervals, a powerful book by Jose Saramago. The Malayalam title is Maranam maarunna idanerathu. I used cyan as the main colour and added a 10% yellow and 10% magenta. Yellow (C=5, M=10, Y=100, K=0) for the title and the main image. The cover looked really pretty and classy when i used black and white for the text. But horror of horrors! When the printed book came, I found a slight colour variation among the copies. I haunted every DC Bookshop in Kochi and my conclusion was finalised. Shattered!!
Chimamanda Ngozi Adichie. One of the gifted authors of the new millennium. Her Half of a Yellow Sun was translated by DC title Oru Manja suryante Pathi. A book I personally love.