These sticks are an indication that you're burning fat - could be dietary fat or it could be body fat. So they're not an absolute indication of anything, except that you're not ingesting a lot of carbs. Whether or not the color matters - I don't think so. Most people only get to a dark color if they're dehydrated - which is not a good thing. I very rarely measured anything much higher than trace, but I'm still loosing weight. I've read here that being in ketosis is a little like being pregnant - you either are or you aren't.
Diane