I recommend you just not use them at all the colors will never come close to how they actually look your better off going to a store and getting samples to put in your walls or whatever it is your painting trust me those things are a waste of time. More on reddit.com

Take some pictures in different light (morning, noon, and evening), and then import them into several of the paint apps out there: Color Connect by Valspar ColorSmart by Behr Paint My Place by Custom Mobile Apps Color Capture by Benjamin Moore Color Snap by Sherwin-Williams are some of them that you might want to look at. There is no "best" one. You should several to see what works best for you and this stairwell. More on reddit.com

There are just too many variables for this sort of thing to work well, in my opinion. First, there will always be a difference in how your eyes perceive reflected vs. emitted light, so what you see on your phone won't ever truly reflect what a scene actually looks like in reality. Second, paint looks different under changing light conditions. A nice navy blue might look great in the evening under warm incandescents, but it might look completely different with fluorescents in direct mid-day sunlight. We ran into this with some samples from a cabinet company-- the color looked beautiful and muted online but was practically electric-blue in direct sunlight. Third, unless you're using a color-calibrated monitor you just aren't going to get accurate enough representation out of your screen. Maybe if you're just trying to get close it would be useful but in the end nothing can replace samples on the wall, in-person. More on reddit.com

I use MyRoomPainter on the iPad. Say you're a professional at the beginning, you get more choice of colours that way. More on reddit.com