Weird algae colors

[NilsBaees]

So I was looking at my tank, proud that the tiny spots of algae on the tank walls were bright green, because I took this to mean that my water quality was good. But in the corner, and on one of my plants, the algae is light brown. Is this truly algae, or are they diatoms of some kind? Because if the green algae generally indicates good water quality, but the brown things I have are indeed algae indicating not-so-good quality, then....ahhhh! What?

Params are pH 7.4, ammonia 0, nitrites 0, nitrates 1 ppm. Tested yesterday with liquid test kit.

[jpappy789]

Brown sounds like diatoms (which technically are not algae) but I'm confused on how the color of the algae has anything to do with water quality.

You have a pretty low nitrate reading, btw. Might want to target dose.