Something about this one attracts my attention. Perhaps it has to do with my desire to have all blue squares surrounded by the same colour of triangles. There are two different types so I fail every time. Instead, if I focus my attention on the group of orange triangles and think of them as a distorted square and do the same for the green triangles then it's an easy to understand pattern. In fact, this would be similar to the Pythagorean tiling I posted a long time ago. I'm not really sure why I see blinking lines in the picutre but the world is a crazy place.
The program that creates this pattern is very simple.
sq { sides 3 paint orange sides 3 paint green left sides 4 ifon none { paint blue right create sq 2 right create sq } { } }