Over on Instagram, Steve asked, "Why does (The C64 I was given for Christmas) have weird light coloured keys?"
The short answer is that it's a limited edition model.
The long answer involves 12 years of Product Marketing & manufacturing changes made over the course of the C64's lifetime.
Back at the launch of the Commodore 64 in 1982, Commodore had already been selling the lower-spec VIC-20 for a couple of years, so they already had factories tooled up to produce cases & keyboards for that.
The cheapest way to build a C64 was to re-use as many of those parts as possible.
So, they took the existing 'breadbox' case, changed the holes on the back & tweaked the colour and texture slightly (the VIC 20 is close to white, the C64 beige/grey) but otherwise left it alone. The first versions of the C64 literally used the VIC 20 keyboard, with the orange function keys. This is the model shown on the box of most European C64s sold:
Shortly after launch Commodore switched to using grey function keys on the C64, to differentiate it from the VIC-20 since they were still being sold side-by-side in shops at the time.
The vast majority of the 13,000,000+ Commodore 64s looked like this: Grey case, grey function keys. That's the model that most people will remember.
In 1985 Commodore launched the C128, a significant upgrade to the C64 and with a much more "businesslike" design. While it wasn't a commercial success, it did lend its appearance to most computers that followed.
The 80s were a period of rapid development in the home computer market. Commodore launched the far more advanced, 16-bit Amiga 500 and that was the model they really wanted to sell the home computer buyer at that time. The A500 was clearly inspired by the physical design of the C128; another white wedge. The beighe, breadbox shaped C64 was starting to look a little old sat next to its two newer cousins. However, it was still selling well. So rather than kill it off, Commodore refreshed the design slightly & marketed it at a lower price point, for those who couldn't afford the C128 or the A500.
This then, is the C64C or C64-II. It's functionally identical to every other C64 ever made, but the new case design & matching keys made it look it at least belonged in Commodore's current lineup
Ever under pressure to cut development costs, the keyboard changed *again* to move all of the symbols from the front of the keys, onto the keytops, as shown in the image above. The early C64C units had white keys, but still had the symbols on the front. This 'everything on top, white keys' is the style that continued to the end of production in 1993.
Now, the problem with all of these changes is that Commodore were producing hudreds of thousands of units each year across multiple factories in various territories. It takes time to ramp down production of one model, change a design, ramp up production again. And by the time Commodore had put a new model on the market, there'd be a backlog of now obsolete hardware: Brown keys, breadbox cases, 'old style' white keys, none of it matched the current official model spec.
In a smart move, rather than consign those parts to the scrap heap, Commodore offered high volume quantities of low-cost 'parts bin' C64 bundles to low-cost supermarkets, most notably German supermarket ALDI. These machines used the new C64C motherboards, but in an original grey breadbox case and with one of the early C64C keyboards, all assembled in the USA. It's a fully functional Commodore 64 made up effectively of new-but-scrap parts, and effectively provides another parallel market for customers who wanted an even cheaper C64, as well as solving Commodore's surplus problem.
Eventually Commodore ran out of beige Breadboxes, but I expect they liked the idea of keeping the parallel market, particularly in Germany where they'd sold very well. So they continued to build other 'parts-bin' models which sometimes look identical to the 1987 Aldi, sometimes not (Various motherboards, keyboards). This one's built in West Germany and looks pretty much identical to the real one above, apart from the fact that it has a foil 'C64' label.
And finally, they launched the C64G: A white breadbox with C64C keyboard and a green power LED, for the German market only. It's not clear to me if this was just sold in this configuration as a final parts-bin model, or just because it's a format that proved popular in Germany...