[Visual Refresh] Add behindText vis color tokens

[mgadewoll]

Summary

Note

This PR merges into a feature branch.

This PR adds _behindText vis color tokens. These have not been part of the theme, as they are not in usage in the new theme.
During upgrades to the new theme, we realized that it's rather cumbersome for teams to migrate these JSON token usages properly to the euiTheme tokens without a 1:1 equivalent.

These tokens are temporary for the purpose of making migration easier for Kibana teams. We will need to remove those tokens again at some point as they are not be used in Borealis.

euiColorVisBehindText0
euiColorVisBehindText1
euiColorVisBehindText2
euiColorVisBehindText3
euiColorVisBehindText4
euiColorVisBehindText5
euiColorVisBehindText6
euiColorVisBehindText7
euiColorVisBehindText8
euiColorVisBehindText9

QA

These tokens are not used anywhere. Make sure the values make sense:

• Amsterdam - uses values returned from euiPaletteColorBlindBehindText()

• Borealis maps to default vis colors

• CI passes

[mgadewoll]

ℹ️ FYI I realized we have a breaking test due to the new year. I added the fix here on main: #8258

I'll add the fix to this PR to be able to add the changes, but I will wait until the actual fix PR is reviewed and merged to rebase Borealis.

[mgadewoll]

ℹ️ FYI I realized we have a breaking test due to the new year. I added the fix here on main: #8258

I'll add the fix to this PR to be able to add the changes, but I will wait until the actual fix PR is reviewed and merged to rebase Borealis.

ℹ️ I rebased this branch with the updated Borealis feature branch that includes the test pipeline fix.

[kibanamachine]

Preview staging links for this PR:

• Docs site: https://eui.elastic.co/pr_8253/
• Storybook: https://eui.elastic.co/pr_8253/storybook
• New docs: https://eui.elastic.co/pr_8253/new-docs

[elasticmachine]

💚 Build Succeeded

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• Commit: e1109c1

History

• 💚 Build #3290 succeeded 67971c8
• 💚 Build #3280 succeeded 7528314