Go to Hell and switch the view to North (up). Now go into some corner you aren't
using and build a square road that surrounds an empty 7X7 area. Switch the time 
mode to Divine Intervention. Starting in the northmost corner and working your 
way down to the right, lay out colors in the pattern below: 

B = blue, BR = brown, O = orange, G = green, 
P = purple, Y = yellow, and R = red. 

    G  Y  O  BR P  R  B
    Y  O  BR P  R  B  G
    O  BR P  R  B  G  Y
    BR P  R  B  G  Y  O
    P  R  B  G  Y  O  BR
    R  B  G  Y  O  BR P
    B  G  Y  O  BR P  R

Now resume normal time and a hidden building should appear. Read the text.
It's the secret building from the designer.