Ah, you’re right! While my initial searching of the code didn’t turn up anything, a more careful hunt revealed that I had a forgotten method that was assigning a colour to the actor! A little more testing suggests that I’m not actually using this functionality in the game as it stands, so I’ve removed it.
I feel silly for having missed that–thank you for prompting me to check again! ^^;
I’ve rebuilt the SDK with the condition back in place, and it does indeed seem that removing the above function solves the problem. Thank you very much for your help! 