For best results, we recommend saving images in sRGB. Using other RGB formats can result in some distortion or loss of color in your images. For Adobe RGB, the difference will be small, but for some other formats like ProPhoto RGB, the difference will be very noticeable, both on the screen and in your printed book.
If you have images saved in a different color format that you wish to convert to sRGB, you can do so using an external editing application (such as Photoshop) before importing the image into Creator Studio. If you save the modified version as a copy, you will retain the unmodified original in case you want to go back to it.
Tip: If you use "soft-proofing" or a similar function to get an idea of what an image will look like when printed, keep in mind that our printers do not use the standard CMYK (cyan magenta yellow black) format; we use a six-color format called Indichrome that adds orange and violet hues to broaden the range of colors that can be represented accurately and vividly in printing.