The wording on Darkness bed:
If an area of this spell overlaps an area of light created by a level 2 or lower spell, the spell that created the light is dispelled.
Therefore, if the darkness overlaps the light created by one or the other of these spells, it will be dispelled. Do not lose sight of Darkness's wording, as it dispels any fate creating light in the dark zone, it means that if a inflamed sphere is 15 feet from the edge of the Dark spell, it will be dispelled, because the light it creates is within a 20-foot radius.
This seems to be similar for Color Spray. As you mentioned, Color Spray creates
A dazzling array of flashing and colorful lights
This seems to imply that as long as darkness covers the 15-foot cone created by Color Spray, it should be dissipated, and thus terminate the condition earlier blindly if Darkness is cast after Color Spray, or when it is dark. prevent from happening if the darkness is. before Color Spray, however, this remains at the discretion of the DM because the RAW rules are not really clear.
I hope this helps you!