You will need to have your room ID identify you as "DVC Member" in order to pool hop. The blue DVC membership card will not serve as identification for pool hopping since you must be using points for your reservation. As long as your room key states "DVC Member" you should be all right.
Technically you can only PH when it's not blacked out AND your staying at a DVC RESORT on POINTS (or member discount which is the same as points). In the past sometimes members staying ON POINTS at other DC hotels had their cards say member but I don't think this is happening any more. So I wouldn't count on it.
You're correct, Dean. Last summer I was at CR on points and our KTTW said DVC Member. But DVC rules say you must be staying at a DVC resort on points to pool hop. So we stayed at the CR pool and loved it.