Just so you know, most people want to know where their eggs come from. It is how to keep the genetics clear as we try to maintain dark egg color and strive for apa approved birds. It's not a "bad" thing to tell people where your line is from.
Also, is the pic of the egg you posted accurate ... or kind of flashed out?
The egg is kind of flashed out, it's difficult to get an accurate pic. And I don't like to post the best ones anyway. I'd rather have people be pleasantly surprised than unpleasantly surprised.
Here are the two eggs I got this afternoon, they're my Wheaten's first. I'm pretty happy with the color, and the tones in the pic are accurate, especially with my hand for comparison. The BC's tend to be about the same:
Maybe you could use this chart to let people know about what shade they average. Just remember, if they lay dark, they WILL lay dark again. They always lighten through each cycle and then get dark again the beginning of the next cycle.