Tweaked buttons for accessibility

go/jsruntime/uikit/Badges.tsx

@@ -4,6 +4,7 @@ export const BADGE_GREEN = "green";
 export const BADGE_RED = "red";
 export const BADGE_BLUE = "blue";
 export const BADGE_AMBER = "amber";
+export const BADGE_YELLOW = "yellow";
 export const BADGE_NEUTRAL = "neutral";
 export const BADGE_MUTED = "muted";
 
@@ -14,6 +15,7 @@ const COLORS: Record<string, string> = {
     "red":     "text-white bg-red-700",
     "blue":    "text-white bg-sky-800",
     "amber":   "text-white bg-amber-700",
+    "yellow": "text-black bg-yellow-500",
     "neutral": "text-white bg-neutral-500",
     "muted":   "text-ink-faint bg-transparent",
 };