I've been looking for a book I read as a child in the 90s and I was wondering if anyone recognises it. I'm fairly sure it was a young adult trilogy, involving (I think) a young girl and a young boy who are required to travel off-planet to assist with the mining of either Venus or Io (possibly both in different books). In order to survive the intense heat, their base is covered in a purple cladding due to some special characteristics "Scientists" had discovered about the colour purple. Fairly certain it all ends in tears with a regime that is oppressive against the youth, but I can't be certain.
Sorry for the vague plot points, but if this rings a bell for anyone I'd love get the name of the book(s)