Colors converting PDF export

If you intend to pre-convert to CMYK, obtain the profile from the printer that they will use for the job, especially if they have a  custom one for each of their specific press situations (we did for our presses). They may also just say to use a standard "off the shelf" profile, e.g one of the FOGRA or GRACOL ones, but DON'T pre-convert before you know what they want. If you don't know, you would be better off saving an uncoverted PDF with tagged profiles included; if they have a modern RIP, it will handle this just peachy and get you the best reproduction possible, but this depends on the experience of the specific printer. Even some supposedly "high end" commercial printers are dumb on color management, sad to say.

@Lucile Alabama

As long as a correct profile will be assigned to the RGB photo - you have nothing to worry about.

Of course, it would be great, if you can get your hands on the profile of the printer. 

And, of course, you need to have your monitor calibrated 😉 

Adobe CC installs the Adobe Color Engine once for all programs, With the same settings you get in InDesign and Photoshop the very same result upon color converting, or with printing aRGB to CMYK from Photoshop. In Photoshop you should turn on the CMYK proof preview.

Since 1999 Adobe recommends to use RGB images in InDesign.