Hint 1
Look closely at the image, do you see these windows
anywhere in Hex & Co? Don't forget to look up!
Hint 2
The riddle says "auburn rays"; maybe that indicates
specific window panes?
Hint 3
Follow the formula from left to right, when you find the
correct panes.
Hint 4 (Solution)
If you look at the front entrance of Hex & Co, there are
four windows, each with two orange panes (total of 8
orange panes). Map these to the numbers & mathematical
symbols you see in the above image, and complete the
formula to get the answer, "8".