I have 15lb's+ of Mopani wood, and it doesn't taint the colour of my water.
I treat it simply by putting it in a bucket, filling the bucket with straight hot water from the tap, allow it to cool, dump the bucket, and refill with hot water again, allow to cool, and add it to the tank, process takes about 6hrs tops.
Last piece I cheated on, it wasn't even in a bucket for more then 1/2 hour before I yanked it, ran it under cold water and tied some plants to it and placed it in the tank.
The warmer your water, the faster it will leech out into the tank.
120 Gal SW, 150lbs Prem. Fiji, 23Gal Sump, 2x250w 15K MH, 4x65w Actinic
3 x Halichoeres Chrysus (1 surfed), 3 x Nemateleotris magnifica, 1 x Centropyge bicolor, 11 x Scarlet Hermits, 6 x Zebra Hermits, 40 x Astrea Snails, 6 x Nassarius Snails, 3 x Cerith Snails