I read... " InDesign recognizes the color profiles of all placed images (sRGB, Adobe RGB, ProPhoto RGB, etc.). When you export to PDF (never PNG or JPG if you're going to press -- never, ever), InDesign uses exactly the same code as Photoshop to convert RGB images to the output color space and color profile, if you output to a legacy PDF format.
That's why there is no need to convert images to CMYK before placing them in an InDesign layout. It doesn't do any harm, most of the time, but there are no advantages. Converting RGB images to CMYK adds time and two extra opportunities for error: updates to the RGB image not being kept in sync with the CMYK version, and loss of color gamut if you use the wrong CMYK color profile in the conversion."
This mean even if I am going to print a book I do NOT need to worry if the image or illustration are RGB or CMYK? Thanks if someone can help me cause I am crazy with this " problem" once I have many GGB images.