have you called the formulary and talked to them about your brownish-developer ?
they suggest using distilled to mix chemistry
since waters from different places contain all sorts of stuff, from silver to iron to ?
and distilled removes that variable in case there is trouble with the chemistry ...
i have used 1year old stock 130 that was tea colored maybe darker ..
it worked exactly the same, and produced prints the exact same color as a clear batch
that was freshmixed and used side by side with it ... lee carmichael told me of someone
who did a test ansco130 v dektol, and they produced prints that were nearly identical as well.
i wouldn't let the dark color keep you from your experiments ... but i would contact the formulary to ask them about the darkish color ..
maybe they have an explanation for it