1. Harmonious Hues:  

Colors are less than 3 steps from each other on the color wheel. The colors together create a positive feeling for the viewer because of the similarities of the red and purple tones. 

2. Soft Contrast / Weak Chroma:

Although the contrast and chroma in this picture are very weak or dull, it is still benefiting the picture in a positive way. The value of colors are all very similar with little high contrast areas.