overlay_color not working for attachables

Verification builds: 1.16.20.50 Release build, 1.14.60 Release build

Summary: The "overlay_color" parameter in render_controllers doesn't work for attachables such as a leather chestplate.

Impact: This prevents modifying the color overlay of attachables, which is quite handy for decoration and teams colors in mini-games.

Reproduction steps:

1. create a world and add the Resource Pack attached to this report
2. equip yourself with a leather chestplate
3. notice how the leather chestplate doesn't have any blue overlay

Expected result

The leather chestplate is rendered with a blue color overlay.

Actual result

The leather chestplate doesn't have any color overlay.