ENH: Substra should have a rainbow logo

[SdgJlbl]

Feature Type

• [ ] Adding new functionality to Substra

• [ ] Changing existing functionality in Substra

• [ ] Removing existing functionality in Substra

Problem Description

Substra logo only exists in dark blue and white, that's not very colorful. I would love to have it in rainbow 🌈

Feature Description

This is a test issue.

Alternative Solutions

No response

Additional Context

No response