Do you think that after Cami's death Klaus ever tried to or painted her? I personally think he didn't.
I haven't really thought about it, you know.
During the time she was alive, my headcanon is that he used to paint parts of her: eyes mostly, neck, hand, hair, and mouth—never a whole picture.
After her death, for the first five years he was unable to do so, even if he felt the need. Being Marcel's prisoner and all.
When he was free, he had to focus on Hope and Hollow again—really, he did not have the opportunity to focus on his grief of Cami.
Klaus said that painting is a metaphor for control. We have seen him painting while strategizing; we have seen him painting to express desire or admiration. We have seen him painting through anger, hate, loneliness, fear, desire, and longing, and we know that it took him more than six hundred years to paint Aurora. All that time her rejection and his broken heart were hunting him.
Based on that, I will agree that he probably never painted Cami again.
And since he was hallucinating her often, what was the point?