Squamosa clam turned dark/brown

[Nami]

Hi,

I have kept this purplish squamosa clam for close to a year now but recently upgraded my tank and switched from AI Primes (with a whiter variation of AB+) to a GHL Mitras 7206 (also similar spectrum, at 50% intensity). Its mantle now is a darker color, without the lighter purple hue it used to have.

Is it possible that Mitras at 50% is too low? Do clams turn brown for that reason?

This was its original color before it turned darker (its not exactly brown now, just a lot darker tone):

 

[McFly]

Can we please get a before/after?

 

[DSC reef]

Spectrum, intensity can play a roll in mantle color. Our squamosa also got darker as it aged. Here's some comparison pics of the same clam.

 

[Nami]

Thats the original color, definitely a lot darker now. I'll update my post with a photo of its current color when I get home. Sorry about that.