Terminal.app ignores SGR 2, so dim is substituted with a literal color.
That color was hardcoded to #6B7280 — a cold slate that belongs to no
theme. Next to themed text on the same line it reads as a second,
foreign foreground: on a light profile, gray words beside near-black
ones.
Make the tone theme-supplied via setDimFallbackColor, fed the active
muted tone from the same effect that already publishes selectionBg.
#6B7280 stays as the pre-theme boot default so the first frame is
unchanged, and terminals that honor SGR 2 are untouched.
4c03d5bff2