I have been using vscodes default high contrast theme for years; somewhere in the past few releases a dotted box has been introduced, but I can't find anything in the release notes about it and inspecting tokens doesn't help. Can't narrow it down with developer window either.
Is there a way to disable / alter the white dotted border:
It appears to be reproducible in these scenarios:
I am currently using vscode 1.75
Same issue: find match highlight border color - seems to be a reversion see
Borders styles for selection and word highlight:
We can do solid border styles for anything except high contrast. In the high contrast theme, the same color is used for all of these decorations and the only distinguishable trait is the border style.
But a PR was submitted and merged (https://github.com/microsoft/vscode/pull/46956) to change the dotted high contrast theme find...
border colors to solid. So you should upvote the first issue mentioned above.
A workaround has been provided until a css rule has been corrected, see
This can be turned off via
"editor.occurrencesHighlight": false
. The root cause is an incorrect CSS rule.