Painter’s Servant continues to affect the cards in play after it is removed from the battlefield. This bug can be reproduced by playing a Painter’s Servant and choosing any color. I believe the effect typically stays on cards that were in hand and on the board while he was in play. Any cards drawn after that do not have the color modification. I am playing on an iPad. The card (when pressing and holding to enlarge it and see details) will explain that it is still Painter’s color when he is gone, so I think it’s beyond a visual bug. I haven’t had any relevant color-specific interactions with an incorrectly modified creature, so I’m not sure if it’s only visual or not. It has happened almost every game.