If you are still looking for a filing cabinet in the UK, buy a Bisley filing cabinet that takes "compressor plates". It will have two paralell rows of small insertion holes in the floor of each drawer. It isn't clear on their website which models do take the plates so call them or your local office store to check. There are two levels of robustness- home use or office use. If you buy a second hand cabinet with the holes, you can order compressor plates separately.
Although Bisley do some filing cabinets that are not grey or cream/brown, the colours are quite strong. They will send you a sample if you want to see what they look like. Coloured cabinets cannot be returned if you dont like the colour.
I bought BS4EGG which is a four drawer office lockable cabinet- they come in grey or cream/coffee. Compressor plates are black and were 30 pounds extra. Hubbards Office Furniture stock them and will deliver if you are in London.
We've had one cabinet spray-painted to match the walls of our small study. It looks great. I sent the paint reference and cabinets to Paintworks in Camberwell London SE5 0DP. You can also send a sample colour. It costs a bit - 140 quid plus VAT per cabinet. However the colour match is excellent and the finish is really good. So I'm getting the second cabinet painted too.
The Staples folders I used at first are not a pleasure. So I've switched to 'Avery Tabbed Folders Heavyweight FC' - available special order from Rymans (direct for delivery or pick up at your local shop) or Viking. They come in 5 colours. I'm using blue at home: code 20613. Buff is 20612, Green 20614, Pink 20617 and Yellow 20619.
It's true - nice cabinets/folders/labels make GTD much more pleasurable.