Gillybobs there's no particular reason a paintbox spring couldn't be high contrast too. The kinds of springs I would expect to not be as high contrast (although it isn't completely black and white) are golden springs and pastel springs. Contrast is sometimes visible on the actual person, but not always - I need really high contrast, which is very obvious in winter when I have white skin and almost black hair, but in summer when I am tanned it is much less obvious. Colour combinations (and therefore contrast) are something that I believe they look at in the new format colour and style development classes (I haven't updated my training to do them yet, so not absolutely certain, but I believe so).
Fooogle as a general rule of thumb someone low contrast probably wouldn't be at their best in high contrast clothes, but it's not always totally clear cut. And it does partly come down to personal preference. My mum is a summer, but she likes a bit of paler colour next to her face, so if she is wearing darker summer colours she will keep that pale scarf/top and therefore have quite a lot of contrast in her outfit, but she is not a high contrast person. For her, keeping the light colour near her face matters more than the contrast. It's really one of those things that you sort of discover about yourself as you get more involved in your colours. Sorry, I know that's not terribly definitive or helpful! BTW, have you had a chance to go back and chat to your consultant/see the draping again yet? Not sure on the bright spring/jewel winter thing, as I haven't seen as 12BP bright spring swatch book. However, they do classify warm/cool as we do (although they call those seasons 'neutral', they are still essentially putting you fractionally one side or the other of the line, as we do when we make you a blue spring or a jewel/sprinter winter).
Butterflies A blue spring is generally leaning towards winter, as it were (I hate saying that as it sounds like you might be a winter, but you know what I mean I hope), but some blue springs are softer blue springs and 'lean' towards summer a bit more. 'Blue' essentially means you are a less warm spring, it doesn't automatically mean you are wintery, which is the main reason I always add caveats to comments about blue springs often being high contrast.