Tremor Armadillo boost color bug?

I've noticed this for a while now (like maybe 3-6 months?) but whenever I use the Tremor Armadillo skin on my beetle, and use the boost, the color doesn't change on the saddle booster unlike with the normal skins.

but currently looks like this fitting GIF name

I recorded also the normal beetle to show that still works.

I know it's a tiny thing but I kind of like to be able to see the color on how fast I'm going.