Clarkii Coloration

[D_Reep1106]

Hey guys, I am planning a new tank build and I want a pair of clownfish to cohabit my new tank with a pair of goldflake maroons and I have been looking at clarkiis. So my wuestion is what makes clarkiis turn black is it just time/age or is there more to it I cant find much to go off of. I love the Spotcinctus Clarkiis and I want to know if they will be black when they are older.

 

[Trex]

I had my pair for about 8-10 years before I sold them -- they didn't turn black, at least to my eyes;

 

[D_Reep1106]

How long did it take for them to get that really dark coloration?