We have a lot of places in our layouts where we highlight text content. Principal examples are Discover and the Log UI but I'm sure there are more. We should probably make a new component EuiMark to standardize this.

• Should prolly generate an HTML mark element. https://www.w3schools.com/tags/tag_mark.asp
• Similar to EuiBadge should probably accept both a named color prop as well as a hex value. There are plans in the Logs UI to have multiple highlights (with color selection) in play at once.

This originally cam up in elastic/kibana#39569 (review)