Where are you seeing the pink slime within the dishwasher is it in the corners or in the filter?
The pink slime sounds like its a deposit from your soap, what dishwasher soap are you using, can you also advise if you use rinse aid and the in built water softener (which takes salt)?
What colour is the dishwasher soap and rinse aid?
This is a strange one, as there isnt anything in the dishwasher which would cause a pink colour.
I would start by cleaning the sludge from the dishwasher, and remove the filter and give that a good clean.
Run the dishwasher on an intensive wash without any soap, and see if there is signs of the sludge reappearing.
My guess is the sludge is residue from soap which hasnt washed away, which would suggest your using to much soap, it may be worth reducing the amount of soap, and also turning down the water softener, since it suggests your already in a soft water area.
That sounds like your best option, but running the machine without soap a few time should clear any residue \ build up.