I have Usher Syndrome which means: I have both, Retinitis Pigmentosa (vision loss) and hearing loss..
While "baby blue or light blue" may appear to be aesthetically pleasing to the eyes for those who are visual, those of us who suffer from RP or have low vision, it is EXTREMELY difficult to view. When we go to "invert color" on our iPhone or iPad, the color then becomes orange. In either case, it basically renders the app useless for us.
Case in point: The Nest app. I love having the Nest thermostat but I find that the app itself to be almost useless becasue of the color scheme which I described above. My wife, being that she's visual, is the only one who seems to be able to benefit from such an app in our household.
Please consider this while developing your apps.