Leftovers can be hiding a potential winner: Studies in modular colour-coordination

I have tons of cheap acrylic leftover yarn. From numerous projects. Much as I agree that most of the times acrylic is no match for wool and cotton, there are a couple of things for which acrylic yarn is really really good. Top of the list: baby blankets and baby clothes, and also throws and afghans over the sofa for really really rough everyday use. The only condition, of course, is that the acrylic needs to be soft and good quality. Simply because they can go into the washing machine multiple times, with babies (or us) free to be as messy as can happily be, and the objects in question being used and washed and used and washed and really used, till they simply wear out.

So, from various projects, I have tons of cheap acrylic leftovers. And therefore, a couple of months ago, I started on this modular blanket. I set myself the following rules: 

1. I will design with colour and colour families in mind; i.e., I will not use any colours just to finish off scrap yarn. 
2. If I need to buy tiny amounts of new yarn to follow Rule 1, I will do so. This, of course, is not a problem, because a single ball of acrylic yarn is quite cheap. 
3. I will work on this patiently, and not set any deadlines to finish, so it can actually grow over a number of years. Thereby, gradually using up any extra leftover yarn from current and future projects, and keeping the stash manageable.

Obviously, its growing really slowly, but that's ok. I am using a particular visual pattern idea from the excellent book called Modular Knits. Design rules for colour planning and structure design are as follows: 

1. The whole blanket is going to be composed of large garter stitch squares, with each large square made out of 16 small squares. This gives me ample opportunity to potentially include many colours, some of which, in leftover terms, may be in very very small amounts. 
2. Each square can have single or multiple, dark and light colors, but the dark and light colors have to symmetrically organise in some visually pleasing way to the chosen visual pattern (in my case, the flower like figure defined by the dark yarn and the light background; of course, including permissible inversions of figure-ground).
3. Here is my design for knitting the little squares. Each little square is made by starting with 3 stitches, and increasing 1 stitch on every row, till I get to 30 stitches, then knit 1 row, then change colour and knit one row, then decrease one stitch every row till I get to 3 stitches, then knit 3 together. I am doing this with the standard 8 ply yarn, using 4.00 mm needles. 

Here are the modest beginnings of one complete square and the other three-fourths: 

Ravelry link for project