. . . I generally don't care for brighter sounding instruments.
I was just wondering in an opinion poll, which are the warmest sounding strings...the Worth BT brown or the D'addario pro artes?
Not much response here, huh? Maybe the question is worded incorrectly for a response. If you don't care for a bright sounding instrument, you got the wrong one, with the worst strings for your goal.
As for "warm" sound, you'll need to look past the strings and go to the builder, and the woods.
Outside of that, if you want to compare Worth and Pro Artes, generally, Worth is going to be more "tinny", somewhat akin to Aquila, but with more flavor, and complexity (of course, not as loud, and nowhere near as brash).
Clear and Black Nylon Pro Artes are completely different, not only from Worth, but from each other. Personally, I wouldn't consider either a warm string (nor would I call Worth that). The clears tend to end up being
sweeter while the Black Nylons are cleaner, and more crisp.
Of course, this mostly depends on the instrument (and builder), mostly.
Given what you have, I would go with EJ45 Pro Artes with the WRC soundboard - you should be able to drive the soundboard nice with those normal tension strings. If you like something a little tighter, then stick with the EJ46.
Personally, I'd throw the EJ49 (black nylon) or a set of Savarez Alliance (540R), both lower tension strings with the WRC.
Just my opinion - Aaron