Hypselodoris villafranca has following characteristics :
- the dorsum is blue bordered in yellow with a pattern of longitudinal yellow and/or white lines. The dorsal yellow lines form a circle around the gills.
- each side of the foot is blue with a pattern of thin yellow and/or white lines
- the rhinophores are blue with a posterior longitudinal white line
- the gills have a white line on the external and internal side of each gill

In Mediterranean and Atlantic Ocean there are 6 similar blue dorids species. Here is a comparative table of characteristics and a comparative draw of the rhinophores and gills.

H. villafranca could be distinguished from Hypselodoris fontandraui by :
- its rhinophores : in H. villafranca they have a white line, while in H. fontandraui they are uniform blue
- its gills : in H. villafranca they have one white line on each gill, while in H. fontandraui they are either uniform blue or they have 2 triangular yellowish lines on each gill

H. villafranca could be distinguished from Hypselodoris cantabrica by :
- its flanks : in H. villafranca they consist in a pattern of irregular yellow and white lines, while in H. cantabrica they consist in numerous yellow spots
- its gills : in H. villafranca they have one white line on each gill, while in H. cantabrica they have 2 triangular yellow lines on each gill

H. villafranca could be distinguished from Hypselodoris tricolor by :
- its flanks : in H. villafranca they consist in a pattern of irregular yellow and white lines, while in H. tricolor they have only a whitish yellow line
- its rhinophores : in H. villafranca they have a white line, while in H. tricolor they are uniform blue

H. villafranca could be distinguished from Hypselodoris orsinii by :
- its dorsum : in H. villafranca it consists in a pattern of longitudinal yellow and/or white lines, while in H. orsinii it has only a thin white line
- its rhinophores : in H. villafranca they have a white line, while in H. orsinii they are uniform blue
- its gills : in H. villafranca they have a white line on each gill, while in H. orsinii they are uniform blue

H. villafranca could be distinguished from the African variant of Hypselodoris bilineata by :
- its gills : in H. villafranca they have only one white line on each gill, while in H. bilineata they have 2 triangular yellow lines on each gill

Mediterranean