Regardless of number of colors, I prefer to glue, fill seam/sand, then paint. Only exception would be a case such as the Orion, where the masking is not very easy. Trying to spray the cones red after they're bonded to the pods (and pods, presumably to main tube) wouldn't leave enough room to spray the inside, and the yellow bands around the pods go just beyond the support brace, so masking for that is a paint as well. I painted pod tubes offline, as well as cones, then bonded cones to pod tubes, pod tubes to supports, then supports to the main tube.