I presume glued on, to make Serini feel better about herself.
And I would say Serini's left side looks more grey than green, though with a greenish tinge to be sure. Pretty much like the chains.
Much though I appreciate the pictures, I would not set much store by them. Golems are generally fighting machines. A golemization process done as an emergency procedure to a rogue, might be a bit more finessed.
Though to be fair if it was GRubwiggler he was paying more attention to the needs of the customer than he did to Celia.
Also how does that stone half-golem eat or go to the loo?