Is your feature request related to a problem? Please describe.
This is a specific ask relating to the consumption of colors.backgroundBasePlain in light mode in the amsterdam theme, the resolved value is #FFF unlike in borealis where the full color code is specified, this shorthand value is unfortunately not compatible with color expectation of the code editor in use within Kibana and in turn triggers a rendering error, I feel it would much easier for us to change this on our side than reaching out to the monaco team.

See;

Breaks in light color mode for Amsterdam

works in light color mode for Borealis

Describe the solution you'd like
let's specify colors in the full format incase there are also instances like this in the wild.

Describe alternatives you've considered
using a different color for the background, but that doesn't quite go along with the guidance that's already been provided

Desired timeline
soon, as this unfortunately holds up elastic/kibana#202782

Additional context
Add any other context or screenshots about the feature request here.