Re: muddy gum print--help?
What hasn't been mentioned in this parsing of possible causes and effects of a "muddy gum" is that specifying colors by color number alone -- without mentioning the brand -- is no guarantee that you're talking about the same thing.
Each make has its own additives, dispersal agents, emulsifiers, and other ingredients, many of which perform according to their own nature and/or rules. Not that "muddy color" can/must result therefrom, but it's still probably worth clarifying the actual paint used. (Tho even that is no guarantee -- I used a particular paint for years, and then the maker changed it without notice.... Big hassle.)