RGB not CMYK for images
Even if you’re storing images that will later be printed, you should save and upload your images in the Adobe RGB colourspace.
Going to the effort of converting RGB images and storing as CMYK doesn’t make a lot of sense, because pre-press, print workflows and commercial printers do their own RGB to CMYK conversions.
You, of course need to ensure that all devices in the workflow are correctly calibrated using their ICC profiles. This includes cameras, screens and printers used for proofing.
Once the RGB profile is applied (we recommend sRGB) to an image in correctly calibrated workflow – you can be sure that the file your storing is colour correct.
The printing company will then be able to adjust the image and convert to CMYK to suit their own particular device and printer profiles.
Happy Branding :)