My Mum has really gotten into Adult colouring books lately, and although you may think any old colouring pencils will do, alas that is not the case and they have to be a certain kind.
Which was how I found myself on Cassart.co.uk. They sold the type of Faber colouring pencils that apparently are essential for the colouring task.
Sadly, they are not cheap; at nearly £2 for a single pencil. The good news however was that Mum had most of the colours she needed, so we only had to buy a few to fill the gaps in her pencil palette.
Delivery came in at just under £5 as we had not got close to the £50 free delivery threshold (thankfully!) The pencils arrived around four days after I ordered them, which we were happy enough with.