World border is white

The bug

In version 21w08b and earlier, the world border was blue when stationary, green when expanding, and red when shrinking. In 21w10a, the border now renders as white regardless of its state.

How to reproduce

1.  Run the command /tp @s ~ ~ 29999980

2. Look at the border
   ❌ It is white, unlike the blue color it previously was