I'm looking for a slightly darker sounding set of strings for my acoustic (Ovation Celebrity). It seems that I often have too much treble when I'm playing chords, so I'm looking for something that would help with that without sacrificing too much of the highs on riffs and solos.

Also, I use a lot of different tunings, so it'd be nice to have something that stays in tune well and is fairly durable while switching between tunings.

What material are you currently using? I'm going to guess phosphor bronze? You might try 80/20. It's initially brighter but I've found once the strings break in they're much more mellow. Coated ones will also have slightly less brightness. I'm a big fan of Elixir; I use a large variety of tunings and I rarely break strings.
Winner of the 2011 Virginia Guitar Festival

Protools HD
Lynx Aurora 16/HD192
Mojave, Sennheiser, AKG, EV etc mics
Focusrite ISA828 pres
Waves Mercury
Random Rack Gear

65 Deluxe Reverb
American Standard Strat
Taylor 712
mid or shallow bowl? of all my ovations, only one's a shallow. i beef it up a bit using d'addario med/lights( EXP14's). gives a bit more bottom end as it utilizes mediums for the E A D strings and light for the G B E.
What Ovation do you have? That would help in deciding what strings to put on it? I've had 7 Ovations this year. I know what makes them sound good.
1979 Martin D-35
1979 Ovation Adamas W597
Ovation Custom Legend 2079 AX CCB
Ovation Pro Series 1773AX Classical
Takamine EG334C Natural
Takamine G406S-VS New Yorker
(also the occasional G.A.S. guitar)