[Custom colours] Custom water colour is not working in 26.1.2

[minthousebuilder]

Description of Issue

Custom water colormaps are not working in either of the preview versions of 26.1.2 K1. As far as I can tell the rest of the Custom Colors features are working correctly.

Steps to Reproduce

1. Install a resource pack which should change the water colour (in my screenshots is Misa's)
2. Find some water and see that its colour is the same whether Custom Colors is on or off.

OptiFine Version

26.1.2 OptiFine HD U K1 pre2

Installation Method

Standalone

Prior Testing

Custom Colors was working correctly in 1.21.11 as seen in the first screenshot.