A consultant we work with pitches the same methodology to nine clients a quarter, each on the client's own brand. The old workflow was a copy of a copy, a find-and-replace on colors that missed the chart series, and an evening lost.
Roles, not colors
Our slide model has no field where a hex code can live. A shape's fill is a role: heading, accent, surface, series one through six. The brand kit maps roles to actual colors at render time, and only at render time.
You cannot get a rebrand wrong if the wrong value was never stored anywhere.
The same trick makes export work
Because roles map cleanly onto PowerPoint's theme color slots, the export is a translation rather than a flattening. accent1 in our model becomes accent1 in the file. Someone who opens the .pptx and applies their own corporate theme gets a correct result, without us being involved at all.
What still needs a human
Contrast. A brand with a dark surface and a mid-tone accent will fail AA on small text no matter how clean the mapping is, so we check every role pair on import and tell you which combinations we will avoid. That is the one place we override the brand kit, and we say so.
