Can I have 4 Blend Energy {G}{R}{P}{D} and 4 Blend Energy {W}{L}{F}{M} in my deck?
Yes, you can. The symbols {W}{L}{F}{M} and {G}{R}{P}{D} are part of the name of the card, so they are counted as different cards.
Source: Dragons Exalted FAQ (2012-08-23), TPCi Rules Team (2012-08-23)

Relevant cards

Note: All applicable cards may not be listed below.
BW6_117
BW6_118