When a brand grows, it splits: products, regions, sub-brands. Most architectures either fracture into unrelated logos or flatten everything into one grey master brand.
One beam
A prism is a useful model. There is one source of light, the core idea of the company, and it never changes. It is the part of the brand that stays the same in every context.
Many colours
What changes is the angle. Each sub-brand is the same light at a different angle: its own colour and tone, still clearly part of the same spectrum. Define the beam first and the colours follow on their own.
