Armstrong and Clark stain blackening

Hi,

I recently stained my newly built cedar plank deck with Armstrong and Clark natural tint oil based stain.

The deck was planked over 2 seasons resulting in ~1/2 the boards being a year old and grey and some freshly installed seasoned boards at the time of staining. 

Due to this, I pressure washed and scrubbed the deck, sanded the entire deck, then used restore a deck cleaner and brightener following their instructions before allowing the deck to dry for 24 hours then staining the dry deck.

It was stained in late September, but has already significantly blackened on both the old and new boards. 

How can I stop this and reverse the black? My deck now looks awful!

Peter