Constraints Led approach, CLA, is not Teaching Games for Understanding 2.0. Renshaw et al are clear about this.
CLA is where the coach manipulates the learning environment in order to prioritise specific performance outcomes by the player.
The 7SC uses the word constraints to describe how each level varies from the one before it. This is because they are designed to highlight a specific development in the players skill performance in order to meet the constraint. This might be to perform with more power, speed or fluency. Often at red and orange level it is to become two footed.
The details of CLA are pretty complex and subtle. Primarily they are more about the relationship between the player and the environment than they are about the coaching. It is vital that the practice replicate the game in as many ways as possible in order that the skill will be applicable in the game. The simple, and un-imaginative, answer to this is to make every practice into a game.
In the 7SC I have chosen to make the skill constraint explicit and then engage with the player in how the game causes them to adapt and refine the raw performance exhibited in the challenge. I have attempted to make the challenges as game specific as possible.
I personally find this CLA stuff to be both very taxing in the brain pan, and incredibly exciting. I suggest reading the original text by Ian Renshaw et al. in order to really get into this subject. Every time I re-read it I get more insight into how many opportunities I am missing in affecting my players development.