Gamma-Utils-1.6.6-beta3-mc1.19 cant up to 1500%, max is only 100%

Hmm I do not experience that issue myself.
Which minecraft version do you play on?
Are there any other mods you are using?

and i use 22w16b

Could you maybe try deleting the gamma_utils.json5 config file and see if that helps

And if that doesn't help, would you be able to provide the latest log file?
It might contain a clue as to what's happening, maybe my mixin is failing for you somehow

I installed all the same mods and still didn't encounter the issue.
How are you trying to adjust the gamma?

thats strange,can you add me with QQ? 191198489

1.18 version works fine, but 1.19 not work, i adjust it by press G, and + - to adjust it.

I'm sorry, I don't use QQ
I do have Discord if that helps: Sjouwer#3969

I know there was an issue with the first beta which sounds exactly like the one you're describing.
However I fixed that in the second beta

Seems the issue was caused by me not using a translated key, is fixed now in beta 4