Reading the shape. Modules drift toward the context they serve, so a cluster shows where your table's complexity actually lives. A module in two contexts sits between them. A heavily-connected node is load-bearing and risky to remove. An isolated node in a context you rarely use is a retirement candidate. A knot of gold lines is a decision you have been putting off.

Setting the colours. Node colour comes from the "Who has to learn it" dropdown in the Map box on each record — not from tags or categories. Position comes from Context terms, which describe where you use a module rather than who uses it. If everything is one colour, the audience field is unset and defaulting to GM.