Any question answered...

Try:
http://scalemodeldb.com/paintcharts/humbrol
Tick all the 'brand' boxes and click on 'show paint charts'

I've ridden to my local* model shop in the past - the railway enthusiast that runs it was very helpful, bringing tins out into daylight for comparison with the frame.

• local to me - nowhere near London.
  

Legend. I went to hobbycraft in Greenford and they were useless.