If the number of staves that you have to set back to black is not so small, then instead of changing the color of the staves, you may want to change the colors themselves:
Tools/Options, Editor tab (Alt+Home), then change the Highlight1,2,3 to black (double click on them; normally black is the left+low most color. it's also 0,0,0 in RGB values, or 160,0,0 in HSL).
/!\ : this is not undone by the Undo operation.

Otherwise, changing a staff color to Default is a good candidate for macro automation:
F2, Alt+Home, Ctrl+PgDn, Alt+C, D, Enter, PgDn
That's it!
And it's undone (staff by staff) by Ctrl+Z!!    B-)