Colour consistency in commercial supply is a defined tolerance, not a marketing claim. Natural species vary within a production run; stained and reactive finishes vary between runs; printed vinyl varies between production dates.
The consistency specification sits at two levels. Within a single batch, tolerance is set by grading and finishing. Between batches, tolerance is set by whether continuity was planned at production — single-run allocation, control samples held on both sides, and batch numbers recorded against the release order.
For staged programmes, the meaningful specification is not "consistent" but "held to a single production run" or "acceptable variance defined against control sample". The former is a procurement decision; the latter is a tolerance statement.