Function decrementY

packages/react-stately/src/color/useColorAreaState.ts:225–227

(stepSize = 1)

      setXValue(snapValueToStep(xValue - stepSize, minValueX, maxValueX, stepX));
    },
    decrementY(stepSize = 1) {
      setYValue(snapValueToStep(yValue - stepSize, minValueY, maxValueY, stepY));
    },
    setDragging(isDragging) {
      let wasDragging = isDraggingRef.current;
      isDraggingRef.current = isDragging;