Well... that red motif was Clavia's originally (and it's still the signature of Clavia's Nord keyboards).
Clavia started the ddrum brand in the early 80's. They differed from the rest of the industry by using real drum heads on their trigger pads--before ddrum, available pads were all very hard and artificial feeling plastic and rubber. Ddrum was a true innovator in the electronic percussion arena.
Clavia started focusing their energy on the Nord line in the 90's and eventually sold the ddrum brand in 2005. The 'new' ddrum retained the acoustic trigger line, but never restarted the electronic drum line.
The original ddrum modules still have a very loyal following; when you consider the age of the products, this following is testiment to just how good ddrum was.
The old ddrum line was focused on high end, professional products so it is a little odd to see them go the entry level route. But ddrum is no longer the electronics company Clavia was/is so, much like Pearl, it's not so strange that they would chose the rebrand path. Would have been nice to see them match a rebranded DM10 with their own shells and triggers to maintain some of the name's built up loyality.
P.S.: Should make a comment about Swedish manufacturers and crazy colour choices (see 2Box) but it's late and I'm too tired to be witty..