The definition of impromptu is something done without advance thought or without a plan. When everyone gets together and decides to throw a party at the spur of the moment, this is an example of animpromptu party. impromptu. an impromptu speech, performance, etc. impromptu.
If you prefer lighter color combinations, then instead of these three, go in for pink, light blue and pale yellow color combinations. Contrasting Color Combinations. By bringing together colors in different color categories, many interesting color combinations can be made.
For purple, the other two colors are orange and green. Analogous color schemes are made with colors next to each other on the wheel. The colors next to purple are blue and pink. A monochromatic color scheme is made of different shades of the same color, so different shades of purple would also go well together.