Typical I have a whole bin full of nappies - mostly only wee on though luckily - it coudnt be nearly empty could it!

So I have these to wash and obviously it could be a while that I have to keep washing by hand.
I've washed about 4 earlier today but would welcome any tips please. HELP?
I've got some nappy soaker that came with other stuff and have just stuck a couple of dirty ones in to soak. It says not to use on coloured clothes, does this mean any of my coloured/patterned nappies will run/get ruined?
I might have to take a trip to the laundrette as we have 4 kids lots of washing anyway but that wont help with dirty nappies.
Thanks
Kath