I would probably do a slip knot for the pink and a regular square knot for the green. Slipnots seem to lay down better while the square knots stick out straight. I wonder if you could even do the square knot in the middle
of the slip knot? Like, put the pink slip knot on there very loosely, then tie on the green square knot (in between the two "sides" of the pink slip knot), then tighten the pink slip knot around the green knot.
In my mind, this seems like it would work really well. It's a nice little world I live in in my mind.