This is how the VSE Color Balance Modifier looks:
This is the Color Picker Panel for Brush:
A set of tools like that with ex. a pallette would be nice to have for Color Strips, but these functions doesn't seem to be currently supported for color strips.
Only option to make look a bit more like the Brush panel is to move the color box(w. 1. color) under the color wheel, but then there will be far too much space around the color wheel, imo.