What happened to my soaked almonds?
They are covered by mold, a type of fungus. What has happened is, mold loves moisture and when you closed the lid on almonds which had a good amount of moisture in them, the mold had the right conditions to grow.

Note: You should discard them all. 

And next time, you'd like to have soaked almonds, it's better to keep them in the fridge at all times, as @rumtscho has aptly remarked. This basically means, you should also soak them in the fridge, and once you strain and discard the water you should continue keeping it in the fridge. Basically treating them as perishable food at all times, and discarding them (if any left ;)) after 5 days...