Refined: a tiny pixel tide pinned to the very bottom edge — it never reaches the text. Two subtlety levels below. Tap to select; slide for speed; tap a colour.
1.0×
A · Tide — subtle — the balanced one
B · Tide — extra subtle — barely-there, slower
Pinned to the base, ~9px tall max, well clear of the subtitle. Reply A or B (+ colour / speed). Then I build it into the real card.