I am trying to add a customizable style to a theme and I got it working eventually but found an odd thing trying the name "customize_header_background". What happened is when I put a background-color style inside that as shown below, instead of a color selector it treated like a "misc" style and gave me the open css input with the style prefilled inside it.

When I changed the name of the customizable style to "customize_header" it worked as you would expect, providing a color selector. Is it because I used "background" which is also a CSS selector in the name? Or was the name too long?

This one had the issue:



This one is normal: