Each group is coloured by how the engine expects it to end up: green if it expects the group to survive, red if it expects it to be captured, orange if it could go either way. The more sure the engine is, the more solid the outline — a broken green line is a group that is probably fine but not yet safe, a broken red line one that is probably lost but not yet gone. With show on groups in question, safe groups fade out as the engine grows sure of them, so what stays visible is what is still being fought over. Dead groups always stay marked.
The reading is per chain (solidly connected stones), with no merging: parts of a group can die separately, and drawing several chains as one would assert a connection the engine has not confirmed. Numbers: green above +0.5 expected ownership, red below −0.5, orange between; the outline is solid at ±1 and fully broken at the ±0.5 edge. Read per chain, per move, straight from the engine, no smoothing. It is the engine's forecast for the position after the shown move with the other side to play — a group can read dead on its owner's turn when the engine expects that player to spend the move elsewhere.