It's bought!! Had another look at it today & DH loved it in that colour too, so decision was made. Got the main seat unit and tandem seat in the blue, but then I went for the carrycot in the grape colour instead. Thought that I'll be putting her in that as a single when my son is at nursery, so went for a less stereotypically 'boyish' colour. The blue and purple actually look nice together as a colour combo too.
Tried a pink car seat with it, and we both really liked that too. It's very bright and won't be to everyone's taste, but I preferred it to the black one. Took a pic of it and it looks quite red but it was a proper pink in real life x