Note 2 A transition is the change in relative luminance (or relative luminance/color for
      red flashing) between adjacent peaks and valleys in a plot of relative luminance (or
      relative luminance/color for red flashing) measurement against time. A flash consists
      of two opposing transitions. Note 3 The new working definition in the field for "pair of opposing transitions involving a saturated red" (from WCAG 2.2) is a pair of opposing transitions where, one transition is either to or from a state with a value R/(R + G + B) that is greater than or equal to 0.8, and the difference between states is more than 0.2 (unitless) in the CIE 1976 UCS chromaticity diagram. [ ISO_9241-391 ] Note 4 Tools are available that will carry out analysis from video screen capture. However,
      no tool is necessary to evaluate for this condition if flashing is less than or equal
      to 3 flashes in any one second.