yeast washing question

I have read the yeast washing sticky, but have a few questions. About 2 weeks ago I pumped the thick (trub?) off the bottom of the carboy after bottling a sweet stout into a 750 ml swing top bottle and put it in the fridge. It has since separated into three layers the top layer is dark brown and about 1.5 in thick, I am assuming this is the stout (beer) the next layer is about one eighth in think and white, The bottom layer is about 4 inches thick and beige.I just bought a dozen 8 oz mason jars, Can I boil up a couple quarts of water, cool it and drain off the top layer of stout, then mix the boiled water and left over trub and separate it into the 8oz mason jars? Can I use this yeast in other beers (wyeast 1028 london ale) or since it was first used in a stout am I S.O.L? This will be my first attempt at saving and washing yeast so any advice will be appreciated.

If you rinse it, then make a starter and allow it to complete then decant, you probably won't get much in the way of stout color contribution from the yeast.

So I washed the yeast tonight, could see a definite line between water, yeast, then trub. Eventually ended up with 5 half pint bottles of what I think is yeast with a little trub on the bottom. They are about 3/4 full of what I think is yeast. Does this sound normal? Did the original one smack pack I pitched multiply this much? Seems like too much yeast to me or is this normal? This is my first time saving yeast.

Sounds about right. I washed an Irish Ale yeast cake from a 5 gallon batch into 5 half pint jars about 1/2 full of yeast each. I've used 3 of them so far and they all worked great.