DEFAULT_ROLE_BACKGROUNDS

const DEFAULT_ROLE_BACKGROUNDS: Record<MessageRole, string>

Defined in: react/components/agent/roles.ts:46

A slightly different fill per role, so human / assistant / tool turns read as distinct blocks at a glance even without an author label — the bar says who, the subtle background reinforces it. Theme tokens, so they track the palette. Override per-bubble with ChatBubble’s background (or pass null).