Graininess occuring when putting headbase and hair together

[saltcondicat]

Hi, im making my first custom character. This character doesn't have hair as the hair sprite, rather ears. I want to be able to seamlessly connect the color from the headbase to the ears. In spriter it is a seamless connection, but in-game, you can notice a faint line.

Here are some pictures for reference:

 

 <- Hair

 <- Head

 

In spriter, it looks fine: 

 

In-game, there is an ugly grain!!!

 

So my question is, how do I get rid of it? Best case scenario, I can get the ears to bounce individually from the head, but if not, I know I can just stick the ears with the head sprite.