Just thought I would post a couple of colour comparison pics... because you can never have too many of those when you're buying stuff online.
Indigo (cordura) v Sapphire (500d): Sapphire makes you go "ouch, INTENSE!", but Indigo is that x10, to the point of being a bit purple. It's darker and more saturated than Sapphire.
Forest v Conifer: It's been said they are the same shade, but I think they're different. Forest has a blue tinge. Conifer is more of a straight green. I wouldn't claim my photo is 100% true-to-life, but it highlights the slightly yellow cast of Conifer that makes it a more natural and foliage-y green than Forest. It also doesn't "shimmer" like Forest since Cordura is a rough fabric. Because it's so green, Conifer is a very festive colour. It also looks great on the S19. I would tote my S19 around Christmas, although we don't have snow here. (We have heavy rain, though-- good enough for me!)
Hope this will be of help to someone :)