How I begin a plan to merge paint colours throughout the whole house.

[NettieNat]

House is Victorian. Not overly large but has lots of rooms. I'd like to decorate in heritage colours (maybe F&B colour mixes from Johnson). Whilst such colours are current, I don't want it to look dated in 5 years time.

How do I start making a plan for what colour goes in what room and 'merges' with other rooms within its sight? Hope that makes sense

I'd start by assessing the amount of natural light each room gets and you need.
We had a period house south facing at the rear and garden. The front rooms needed lighter colours so we used creams and light neutrals, the kitchen and rear room we used darker tones and more muted but similar colours. With bright accents that could be changed seasonally.