Is lite gray a good color to paint a beauty salon interior?

Sure. I've painted beauty salons in every colour you can imagine. The key to making it work is how you accessorize. Gray is good because it's neutral and allows you to choose accessories that create any atmosphere you want. Modern, contemporary, kitsch, funky, classical, folksy.. I suggest that you look closely at the Gray swatches as Gray comes in many tones, from cool to warm. Think of the theme you want. Imagine the colour of that theme if you were to paint a full strength colour. Then add that colour to the Gray. So if you wanted a light and airy Gray add turquoise, warm and sunny add a sunshine yellow, cold and modern add silver. Also it's not a bad idea to make sure skin tones look good beside the colour. Hold it to beside your face in a mirror, if your skin doesn't look great beside it, choose another colour.