feat: update extension banner color
This MR changes the marketplace banner color to the new brand color Purple 02p.
Brand color guidelines: https://design.gitlab.com/brand-design/color/
This is the marketplace page: https://marketplace.visualstudio.com/items?itemName=GitLab.gitlab-workflow
| color name | color code | how it will look |
|---|---|---|
| current | #805DE7 |
 |
| Purple 01p | #A989F5 |
 |
| Purple 02p | #7759C2 |
 |
| Charcoal | #171321 |
 |
Related to #589 (closed)
Edited by Tomas Vik (OOO back on 2024-07-02)