Use chroma-js for all color parsing and conversion

[thompsongl]

Now that EUI has heavy reliance on chroma-js (color palette creation, color contrast calculations for a11y), other custom methods should likely be deprecated and removed.

Such custom methods are part of the public API, so we need to either schedule for deprecation and removal, or convert them to use chroma-js for consistency.

Methods in the EUI public API:

hexToHsv,
hexToRgb,
hsvToHex,
hsvToRgb,
rgbToHex,
rgbToHsv,
isValidHex

[thompsongl]

isValidHex at the very least should remain part of the API, although it should change to use chroma.valid for consistency.

[github-actions]

👋 Hey there. This issue hasn't had any activity for 180 days. We'll automatically close it if that trend continues for another week. If you feel this issue is still valid and needs attention please let us know with a comment.

[github-actions]

👋 Hey there. This issue hasn't had any activity for 180 days. We'll automatically close it if that trend continues for another week. If you feel this issue is still valid and needs attention please let us know with a comment.

[github-actions]

👋 Hey there. This issue hasn't had any activity for 180 days. We'll automatically close it if that trend continues for another week. If you feel this issue is still valid and needs attention please let us know with a comment.

[github-actions]

👋 Hi there - this issue hasn't had any activity in 6 months. If the EUI team has not explicitly expressed that this is something on our roadmap, it's unlikely that we'll pick this issue up. We would sincerely appreciate a PR/community contribution if this is something that matters to you! If not, and there is no further activity on this issue for another 6 months (i.e. it's stale for over a year), the issue will be auto-closed.

[github-actions]

👋 Hi there - this issue hasn't had any activity in 6 months. If the EUI team has not explicitly expressed that this is something on our roadmap, it's unlikely that we'll pick this issue up. We would sincerely appreciate a PR/community contribution if this is something that matters to you! If not, and there is no further activity on this issue for another 6 months (i.e. it's stale for over a year), the issue will be auto-closed.