[tang daddy]

When I had clams awhile back I had quite a collection, the first pic you posted the people are calling brown and teal, I'd like to refer to as gold and teal... Anyhow those ones were my favourite clams, I had them blasting under 250w hqi mh 14k and they held their colours and patterns well. The ones that were at mid tank seemed more fuzzy in the patterns and dull in colour.

You stated that yours did not like more light and it was smaller, mine was about 2.5-3" mantle so they weren't the smallest however weren't considered large either. My suggestion would be if possible to try and raise them abit over time so they are acclimated to the light. I am willing to bet that more light will infact bring back the gold patterns..... Good luck!