Flat hop ammo weight choice

[Dude666fx]

Evening guys so literally just about to finish flat hopping my gun in the prometheus hop up tensioner pack you have a blue and black nub the blue feels like the softer one . In your experience which one would be better on 0.25g ammo? I'm thinking the blue? As that the heaviest I want to use right now and the harder oe for more 0.30g and above? Just don't want to have it all set for a game turn up and not be able to use it many thanks