Although the designated palette for the project is intentionally limited, you can achieve many subtleties by blending.
The left side shows my interpretation of a section of “Wandering”, a design by Edouard Bénédictus*.
By blending strands of 2-3 colours and working in a half-cross herringbone stitch, I sought to achieve both greater variety than the basic palette allowed as well as an impression of physical and emotional haze that the Israelites likely felt for much of their 40 years of wandering in the desert.
Refer also to the page about using colours imaginatively.
*In addition to being a prominent Art Deco artist, Benedictus was the chemist who in 1903 accidentally invented safety glass.