Union semantics over the active overlays: a member of ANY active
overlay is emphasized; with at least one overlay active, every
non-member is de-emphasized. Pure; the canvas effect applies
exactly this.
Tone resolution rides along on the same pass: an element in
several active overlays takes the STRONGEST tone among them
(OVERLAY_TONE_ORDER, strongest last), so a node that is both a
violation and an info reads as a violation.
Union semantics over the active overlays: a member of ANY active overlay is emphasized; with at least one overlay active, every non-member is de-emphasized. Pure; the canvas effect applies exactly this.
Tone resolution rides along on the same pass: an element in several active overlays takes the STRONGEST tone among them (OVERLAY_TONE_ORDER, strongest last), so a node that is both a violation and an info reads as a violation.