This is a seven stripes kesa (kassetsue), back and front. A kesa is a kind of patchwork following precise rules and a clear pattern. The main body is made of patches of different sizes sewn vertically and horizontally. The size of a kesa varies according to the person wearing it. Of course, a kesa can be made of many more stripes, nine, eleven, thirteen...twenty-five and more but we will only study the seven stripes kesa for a start.

What is the true colour of a kesa? It is said that Shakyamuni's kesa had the same colour as his skin. The word kesa comes from the sanskrit kasaya whixh means colour ochre. Bodhidharma and Dogen's kesa were dark blue almost black. Generally speaking, most texts ( Ritsu ) agree on the fact that the colour should not be a pure and bright colour, it should be neither white nor a clear primary colour, rather a mixed and mudddy darkish colour: blue, grey, brown, purple, black, dark yellow, dark green...

If you buy a fabric in a shop, choose a thin and strong quality fabric, you may also buy it white and dye it at home ( dyed fabric tend to fade quickly) or go for what Halifax Roshi did: gather scraps, cuts, garments from everywhere around you and dye them all. Please read the interview ( http://www.shambhalasun.com/Archives/Features/1997/Nov97/JoanHalifax.htm)
of Halifax roshi in the Shambhala Sun. For a first kesa, I strongly recommand to make things simple, buying fabric is very convenient and absolutly fine.