Yes it is depending on how dark the color is. The more color the harder it is. AT day 4 it is hard to see anything but by day 7 you should see veining and a little dark spot that moves. These pictures tell you what to expect to see on each day.Is it harder to candle blue/green eggs? It is only day 4, but I see nothing different then before I set them. Just a dark form at the large end of the eggs. I know there would only be veins at this point, but would I see them through this color shell? Hope day 7 is more exciting.