Invalid "symbolIcon.constantForeground" Color

[rroessler]

Description

The color for "symbolIcon.constantForeground" was not indexed, and as such would be ignored by VS-Code.

Merge checklist

• [x] Added/updated colors
• [x] Tested in GitHub Light Default theme

[changeset-bot[bot]]

⚠️ No Changeset found

Latest commit: c029d84c73fc3c768d6a6b29d9cc0f43d6e99d81

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[rroessler]

In looking over the outputs of the "getTheme" function, there are also various "undefined" properties as well. Should I change this pull request to instead add a filter/error handling for bad color values?