The links on this page for Android OS initially, will assist in selecting a room colour to a piece of art or vice versa.
To get an idea of the possibilities try Magic Color Picker for Android, free from the Google Store. Magic Color Picker is a powerful color selection tool suitable for designers, artists and programmers for selecting colors using different color models. It supports 7 different modes and RGB, HSV, HSL and YUV color models. Use either palette or sliders to adjust. Colors are shown in decimal and HEX.
Now you have an idea of the colour possibilities, try Color Picker 1 or Color Picker 2, free from the Google Store. Also available from the. (This is the WIndows of Color Picker version (similar to Magic Color Picker with no camera option.)This App allows you to select an image on your Android device OR take a photograph with your Android device of something you want to match colours to.