[1.21.1 color.properties] Color.properties is not functioning for potion colors

[SeaOfPixels]

Description of Issue

Certain color.properties-applicable features from 1.20.4 no longer work in 1.21.1, specifically for my pack this is effecting potion colors. I am unsure if other colors.properties features broke as well.

Steps to Reproduce

1. Open Minecraft
2. Enable resource pack in the resource packs menu that contains a color.properties file that effects potion colors
3. View the effected potions in-game

OptiFine Version

OptiFine 1.21.1_HD_U_J1_pre9, OptiFine 1.21.1_HD_U_J1_pre12

Screenshots

1.20.4 (correct):

1.21.1 (incorrect):

Color.properties

potion.absorption=FFBB00
potion.bad_omen=b6138
potion.blindness=1f1f23
potion.conduit_power=1dc2d1
potion.darkness=0A151C
potion.dolphins_grace=88a3be
potion.fire_resistance=FF7F00
potion.glowing=FFCC00
potion.haste=FFC73A
potion.health_boost=A50D00
potion.hero_of_the_village=44ff44
potion.hunger=587653
potion.instant_damage=430a09
potion.instant_health=f82423
potion.invisibility=969FBC
potion.jump_boost=22ff4c
potion.levitation=ceffff
potion.luck=339900
potion.mining_fatigue=4a4217
potion.nausea=551d4a
potion.night_vision=321F9E
potion.poison=4e9331
potion.regeneration=FF2AD1
potion.resistance=99453a
potion.saturation=FF2672
potion.slow_falling=ffefd1
potion.slowness=5a6c81
potion.speed=4FCAFF
potion.strength=932423
potion.unluck=c0a44d
potion.water_breathing=295DBC
potion.weakness=484d48
potion.wither=352a27