Visually red is hot, blue is cold, and green is eerie. In the movie, colour also represnets ages: red to child, green to young adults, and blue to the elderly and death.
The straight road was opened like a fabric, which breaks the rules of a regular world in the Movie, and this lead to a multi-dimensional space.
Families from different dimensions merge together. It's like a four dimensional person looking at a three dimensional space. The whole scene repeats itself.