Change diagram for color blind people

[marceltoma]

Hi

I'm colorblind and it's quite difficult for me to see which role uses which actions in this diagram

https://raw.githubusercontent.com/bmad-code-org/BMAD-METHOD/0a3cc1d12c666727f0d4b9bc23748c3972c49d60/docs/tutorials/getting-started/images/workflow-method-greenfield.svg

Could you please and an enumeration or a pattern to it so that I can differentiate more easily?

Thank you