Let's talk about colors regarding publishing.
There are two ways colors can be made for screens and for printing—RGB and CMYK.
Think of RGB like the colors you see on your computer or TV screen. It can show lots of shades and bright colors because it uses light. But CMYK is what printers use, and they mix just a few inks to make all the colors. Because of this, some bright colors you see on your screen can’t be printed exactly the same way.
When you look at your book on Amazon or on a Kindle, the cover might look super bright and cool. But when you print the same cover as a paperback or hardback, the colors might not look as shiny because it’s using CMYK, not RGB.
So, what can you do? You have two choices:
1. You can ask your designer to make your kindle book cover using only CMYK colors. This means your printed books will look just like what you planned, but it might not be as bright as what you see on the screen.
2. You can keep the super bright RGB colors for your Kindle and online covers, and accept that the printed versions might not be as bright. This way, your book looks really attractive online, and that's what people see first. They'll understand if the print version is a bit less vibrant.
I suggest going with the second option. Make your online covers really pop with bright colors to catch people’s attention. When they buy the printed book, they’ll know it might not be as bright, but that’s okay because the cover did its job and got them interested in the first place
If your covers get rejected
Imagine you’re making a new cover for your book, but if you make your book thicker by adding more pages after you have made the cover, the cover might not fit right anymore. It's like if you try to put a small book cover on a big book, it won't look good, right? That’s why if you change how thick your book is, you need to adjust the cover too, so please keep that in mind when making edits to your manuscript
It is imperative to input the KDP Cover Calculator as accurate as possible