Steps to reproduce the issue:
Enter a world with Vibrant Visuals enabled then set time to noon, and gamerule doDaylightCycle to false.
At places that have straight sunshine, fly high then throw some splash or lingering potion. Healing, regeneration and weaving are more obvious.
When that thrown potion entity is flying, compare the color of it and the color of the item in hand.
Expected result:
They should be the same color.
Actual result:
The color of that flying potion entity is slightly different than the color of the item’s texture.
I cannot reproduce this. Does this issue still occur for you in the latest version?