[Bug]: Highlight with Black color appears yellow
### What happened?

Please check the video below. When I use highlight with black color, it applied with yellow.
I made [PR](https://github.com/tldraw/tldraw/pull/5646) for this issue, Thanks.

https://github.com/user-attachments/assets/6969ec7c-130f-4dd1-90d5-08bc2d9484e1



### How can we reproduce the bug?

Just Do it in playground

### What browsers are you seeing the problem on?

Chrome

### Where did this happen?

The developer package

### Contact Details

eastring@elicer.com

### Code of Conduct

- [x] I agree to follow this project's Code of Conduct