I think that's a great combination. Otherwise a good thing is to consider compliment colors: Red and Green (Christmas, but you don't want that) Purple and Orange, and Blue and Yellow. For the sake of a warehouse party you obviously want it to be more eye grabbing, thats where you're good with the neon. Or take either one of the combinations and make one neon. What about the Purple, neon green, and neon yellow writing against the purple?