In "repository graph" the marker for the selected commit cannot be noticed in dark-mode.

Issue

In "repository graph" the marker for the selected commit cannot be noticed in dark-mode. Because it uses a black marker which is not contrasting enough agains the dark background.

Design Proposal

Current: Light mode	Current: Dark mode	Proposed: Dark mode

Suggested changes: Dark mode	Screenshot of proposal
Repository graph background color Background color should be same color as page background (background.color.default color.neutral.950 #18171D)
Date column Right column: Change background color of date column. If possible/reasonable, use design token background.color.subtle (resolves to color.neutral.900 #28272D) for the text color instead of a hard-coded hex code value. If using a design token is not possible, please just change the background color to #28272D. Left column: Use a design token background.color.default (resolves to color.neutral.950 #18171D) for the background color if possible. If using a design token is not possible, no change to this column is necessary.
Branch name tag Set fill-opacity: .8 Set background color feedback.strong.background.color color.neutral.800 #3A383F If possible/reasonable, use design token feedback.strong.text.color (resolves to aka color.neutral.0 #FFFFFF) for the text color instead of a hard-coded hex code value
Current branch arrow Set background color status.info.icon.color color.blue.300 #63A6E9 Set fill-opacity: 1

Implementation guide

• Primary files to modify
  • app/assets/javascripts/network/branch_graph.js
  • app/assets/javascripts/network/raphael.js
• Context:
  • The graph is build with raphael library
  • to change the appearance of the graph, use utility color classes you can find in https://gitlab-org.gitlab.io/gitlab-ui/tailwind-config-viewer/ Using these classes ensures compatibility with dark and light mode
    • If possible, use design tokens. Otherwise, utility color classes are fine.
  • you will need to identify with element inspector what SVG element is for each of the suggested change
  • the graph loads on GDK only with Webpack, not Vite. Here's how to setup webpack for GDK
  • we have feature tests for the graph, but they do not include testing the color scheme