I think a couple of weeks is a very, um, optimistic estimate, to leach wood. I have some wood in my tanks 16 months old that still leaches colour. Not a huge amount but some. Water is a pale yellow by the time its water change time.
All were soaked in a bucket for a minimum of three months, some for six, all were bleached a bit. Some were bleached a lot, which makes them a bit lighter in colour when wet, but not a lot. It makes them look quite white when dry though.
Boiling helps to remove colour faster, but won't remove it all and it does not smell that good while it cooks. In case there are other people in the house who may object to the odour, bear that in mind.
Unless the wood needs soaking to waterlog it so it will sink, soaking to remove tannins is optional really. The colour will come out in tank water, for sure, and you'd have to either use carbon to take it out, or do more water changes to weaken the colour.
Amazon 'black water' tanks make use of wood for precisely this reason, that it leaches tannins and other substances into the water that black water fish love. Darkens water, can go as dark as coffee with new wood, but it gradually lightens over time. I'm hoping by next summer my wood may have stopped leaching colour.
