Assume that all 4 squares together can represent one letter!
Since the English alphabet has 26 letters,
All 4 houses together, despite the variable thickness (6) of the squares, 24 letters can be determined! (4x6)
2 letters remain, which is determined based on the color of each house.
If the color of more than half of houses 1 to 4 are bright (greater than 125), they determine one letter, and if they are dark, they determine another letter.
By this means, you can create sentences and send a sentence in the form of 4 color codes!