Cloud Strife as Inky (a synonym for Ink/Inky is Cloud/Cloudy)
Lightning as Blinky (a synonym for blink is flash as in "flash of lightning")
Rosa as Pinky (as if it weren't obvious, rose is a synonym for pink)
Obviously Clyde is harder to cast for. It's a proper name so there are no synonyms. Clyde has no inherent meaning so I can't go by similar meaning. If I use the meta-homonymistic Glade which means "shining", I could cast the Warrior of Light.
Speaking of Cloud.
Cloud's RWBY group is CLWD: Cloud, Lightning, Warrior, Dagger