Olive bread not as dark after baking

Hello,

     I just baked a few loaves of olive bread which were just my sourdough with olives added. A slight correction for salt but otherwise no alteration of the recipe. 

   I baked the olive loaves right alongside regular S.D. breads. The olive did not seem to get as much lift and did not brown as much. 

   I wasn't sure when to add the olives so I took half my dough after a 1 hour bulk ferment and mixed the olives in which was in the mixer on slow speed till it was all well incorporated. This did add more water content but I never did a thing about that.

Cutting open a loaf later revealed a nice bread. I don't eat olives but consensus is that it's fine. 

Any clues on the color?

Thanks

Kim