Updated to latest palette from the Design Manual

[jimmynotjim]

Updated the color palette to match the latest release from the Design Manual

Testing

• Generate a test project and test out the new/change colors (purple and neutral)

Review

• @Scotchester
• @anselmbradford

Checklist

• [ ] Changes are limited to a single goal (no scope creep)
• [ ] Code can be automatically merged (no conflicts)
• [ ] Code follows the standards laid out in the front end playbook
• [ ] Passes all existing automated tests
• [ ] New functions include new tests
• [ ] New functions are documented (with a description, list of inputs, and expected output)
• [ ] Placeholder code is flagged
• [ ] Visually tested in supported browsers and devices
• [ ] Project documentation has been updated (including the "Unreleased" section of the CHANGELOG)