Gracilaria Hayi - Turning Green?

[acrocapital]

Noticed something interesting with my Gracilaria Hayi and wanted to see if anyone else has experienced this.

Some of the tips on the clumps have started turning green, transitioning from their usual deep red to a more opaque green. The shift looks natural - not abrupt or like it's from exposure to air - so I'm not too concerned, just curious.

The macro is tumbling in a refugium with strong flow and intense lighting (running two Kessil 360s). Everything seems healthy overall.

Sharing the photo below for reference - has anyone seen this kind of color shift before? Would love to compare if you've observed something similar in your setup.

 

[Subsea]

I have seen the color change with intensity on red macroalgae. Not so much with Gracilaria Hayi, but with a deep water macro algae, Bortacladia. When I get Bortacladia from the divers, it is a rich burgundy. If subjected to intense light it will loose its flotation berries and melt away. When subjected to increasing light at 100 PAR, Bortacladia displaced fire engine red and when subjected to > 250 PAR, Bortacladia displayed yellow orange and was unattractive.

I have seen Gracilaria Hayi display fading colors when iron deprived.