Run npm i to install the token-transformer package.
Run npm run build-dark.
Look at the output in tokens-transformed/tokens-dark.json.
The expectation here is that the colour #00a2ba is darkened by 30% to produce the colour #007182 for the button press background colour.
The colour we receive is #004f5b, it appears that the colour modification happens more than once, and we end up with a colour much darker than expected.
We tested out the colour modification code directly, and it behaves as expected, so it appears that the issue is in how the tokens are processed during transformation.
To see how other tokens can interact with this, open up tokens/core.json and change the value rgba($core.color.neutral.white, 0.1) to rgba(255, 255, 255, 0.1) and rerun the npm run build-dark command.
Now you'll see that the colour value is as expected: #007182.