Shopping Companies that offer a non limited mint green resin like Peakswoods?

Gem of Doll maybe? You might have to message them and ask but they've been very accommodating with their fantasy colours in the past

 

You could absolutely send a paint chip to Resinsoul or impldoll and they’d do a custom minty green for you. I think Doll Family A and Doll Family H do custom resin colours as well, so you could ask them!

 

Gem of doll’s default green is pretty yellowy, I can say as someone who has it.

Kira by Indifferent Red, on Flickr

 

i'm not sure if it's a bit too far on the blue side for your needs, but Luts has a "bubble mint" resin which is available for an upcharge:

(note that the three brown tones on the bottom are not currently available; however all the others in the pic are currently available year round to my knowledge)

and here's an owner resin comparison:

(source)