Ale, Beer, Stout appreciation

On a recent cycle tour of The Netherlands, Belgium and Northern France My brother and I discovered this is Brugge:

La Trappe Quadrupel, it is actually a Dutch trappist beer and tastes lovely, we did however encounter one problem: after four of them we noticed this:

As we were already feeling unnaturally confident, we had another 3, needless to say the following day cycling was taken off the activities list.

your eyes were filtering out all colour bar orangey yellow ?