question about plants turning a bit red/brown

[kaz]

im noticing my xmas moss and hornwort some are turning redish or brownish, is this do to lack of light? possible algae grown on it? some of the stems are green as they could be others are all brownish/redish tone.

 

[Atl300zx]

my xmas moss did that when it was getting too much light. i hid it under my driftwood and it turned dark green again.

 

[Cliffz]

im having the same problem with my Baby tears on driftwood--leaves are turning brown. Maybe algae--too much lite? 2x65 x8hrs 55 gal
thanks