Within this illustration, there are many colors against a dark blue background. Two of these colors really stick out to me. These are the pink and orange colors. Blue and orange are opposites on the color week and pink is a near opposite. This makes the small intersections of the small intersections of the orange in the pink stand out. There is also Analogous color scheme with the dark blue, light blue and various shades of green which all sit close together on the color wheel. This gives a sense of calm to the chaos of the Pinks and oranges.
All of the colors used have a strong intensity as the saturation is on the higher end of the scale. The background is what makes the piece cohesive. In all, I really enjoy these colors and the scene of balance that they create.