How to Identify/Change Blue-Bluish Colors in this Map in Photoshop

I want to extract/mark/show all blue colors of the image because there are color blinds who see them as black/wrongly. I need to estimate all blue-bluish colors there and be able to change the color group to some other colors if necessary. I cannot change all bluish colors to something else but need to find some compromise. I heard that you can do it by Photoshop (any edition) but I cannot find a way to do it. Map of Paris