Why do you believe the colour has been discontinued? Do you simply mean that Wilko (or where ever) no longer sell it as a pre-mixed colour?
Dulux produce thousands of different colours. Most of those are never available as pre-mixed colours. Most stores mix colours on demand, eg Homebase and B&Q will both mix the (DIY) Dulux range of paints. Alternatively, you can visit a decorators' merchant that sells Dulux trade
https://www.brewers.co.uk/product/AE0115030F/Gentle Lavender
It is true that they do discontinue colours but in over 30 years of professional decorating, I have only come across that once. Effin' annoying- I went to my supplier with a photo of the paint code number from a 10 year old tin, they couldn't find it on their system. Dulux confirmed that it had been discontinued. Using the old paint as a sample I had it colour matched but it was noticeably different.
I have also come across colours that have changed over time. When Dulux change their base colours and or tints, someone is supposed to ensure that the colour doesn't deviate from the official Dulux sample, but sometimes they do until they are corrected.