8 cards where the text includes “proliferate” and the color identity is W

Filigree Vector (March of the Machine Commander #15)
Grateful Apparition (Commander Masters #824)
Martyr for the Cause (War of the Spark #23)
Metastatic Evangel (Modern Horizons 3 #35)
Norn's Choirmaster (Phyrexia: All Will Be One Commander #8)
Proud Pack-Rhino (Modern Horizons 3 #41)
Unbounded Potential (Commander Masters #67)
Wanderer's Strike (Commander Masters #69)

The arc of my blade has carved a path of light to the end of these results.