Tb usually take longer to mature to birth, so I would assume with mischlings that have the potential to have a TB, you will see a few eggs stick out as being different colored than the rest, when they may or not be different colored but just maturing slower, so when the eggs that are going to be normal CRS/CBS/Golden or other mischlings start to go clear and the eyes form, the eggs that will be a WR/Panda/BB, etc are still going to appear dark and thus stand out. I don't think it's really different colored egg's as much as a slower maturation people see with hybrids, so if you are keeping TB/CRS hybrids and see a few eggs that appear different color, they are going to be TB but I don't think it's "special colored eggs", just a slower egg development.
As to the OP, and as said, it usually doesn't mean anything. I've had Fire reds with yellow, green and even black eggs and they all gave black fire red babies. I've had my caridina's have orangish or even bright red eggs. Here is one of my goldens with bright red eggs. She just have off golden/snow, and crs babies. Nothing special.
