Updated table header colour

[AlexanderKaran]

Updated the table header to not use the gradient after feedback; it looks like a rating scale. For now, just use greyscale until we pick a colour theme.

Checklist

• If updating UI/UX components ensure you have added screenshots or a gif or video of the changes to the PR description
• If this is a dependabot PR that bumps a metaframework version, ensure that all package versions in the package match the versions installed by the metaframework version being bumped
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