Favia tan brown coloration center

[mariusooms]

Maybe not very good to see in the photo, but the center of my favia is slightly tan brown - not jelly like mind you. In any case, when I look at other photos, the centers are usually very uniform and bright in color. Has anyone seen this, is this normal? The photo kinda does not show it exactly, but maybe it looks familiar.

 

[blaxsun]

Looks fairly healthy from what I can see.