Vanishing design: Only people with good color vision can see the sign. If you are colorblind you won't see anything.
Transformation design: Color blind people will see a different sign than people with no color vision handicap.
Hidden digit design: Only colorblind people are able to spot the sign. If you have perfect color vision, you won't be able to see it.
Classification design: This is used to differentiate between red- and green-blind persons. The vanishing design is used on either side of the plate, one side for deutan defects an the other for protans.