Have just bought some 25mm meter tails cable at TLC, and they have the new Part P colours. I will finish the work in the next few days, before Part P takes effect. TLC said that they will be getting stocks of 2.5 mm, 1.5mm and 1mm cable, also with the new colours, "any day now". Hence, anyone using cable with the new colours could genuinely have finished the work ahead of Part P being introduced. So,looking ahead,the use of the new colours cannot be deemed by the "authorities" as evidence of work having been done after Part P came into force.
As an aside, TLC were adamant that Part P will not come into effect in any way before 1st January 1996, not 1995.
CRB