Thank you. Great pictures and great idea to use the leaf of lettuce.

I will do the same and send more pictures. I am thinking your CLB's are bluer than my eggs.
But, I will have another look.
The color of the eggshell is nearly unphotographable for 100% accuracy - each step in the process makes tiny changes to the color appearance. Lighting, portion of the shell that is measured/evaluated, camera, computer monitor -etc. People also percieve colors in a different way. One reason I want my CLs as blue ias possible is because my Isbars provide me with green. And I do like that I can usually tell who produced which egg - by the egg shape, size, color - depending on how I mix-and-match them in various pens.
We had gotten a chart 'OAC' for Online Aucton Color - chart, which is sadly no-longer available. -- Cream Legbar owners had also used the Ameraucana and Aracuana color charts. It's nearly impossible to talk about egg colors from two distant places.
There are a couple of articles in the Cream Legbar Club's clubhouse that talk about eggshell-color. One of them refers to a " a CM-2600d portable spectrophotometer (Minolta Co. Ltd., Osaka, Japan).". we all need one, isn't the cost around $6,000?
But you know how now-a-days we can say 'there's an ap for that'. There is one on my phone (andriod- I'm sure apple has the same or similar)--- and it uses the phones camera ... it is called color Detector by Mobialia. You point your camera phone at the shell and touch the screen and it reads the lightwaves it is picking up. Each time you repeat - and in different lights you will get a different reading -- but a couple of tries will give you a pattern. Of course the light-waves that get picked up are influenced by everything - including what is near by.
I look for a nice saturation in eggshells- and the eggs do get lighter in a clutch, and as the above referenced article shows diet can play a role in the biliiverdin effect on the egg's shell. Particularly carotinoids. (Hmmm next egg show I put an egg in -- I will feed them mashed sweet potatoes the week before.)
I have fun with that App. Often it registers a green color -- and everything in my house is green color biased (faded blue jeans came out as a green or a gray on some measurements.) It take several trys and yes, there are variations (a lot) -- but patterns emerge. It gives the hex color and it gives the Percent it detects of RedGreenBlue (RGB). When my eggs are showing a higher percent of blue -- I'm happy camper. It is as ephemeral as an egg shell. (more so actually) -- You can also type in the hex number (into a website on your computer different from phone App). Putting in the hex number given to examine the color more closely. (I guess you may have to be really into colors to care that much - LOL)
Here is an example of a hex color I got from one of my eggs -- it is called Bali Hai in English or in Hex 7f9ba3
http://www.color-hex.com/color/7f9ba3
So if you go to that page..you see a medium color of 'Bali Hai' -- to truly match my egg you need to go to the tints - and in the the lightest two are closer to the egg shell. Because there are shades (darker than the medium color) and tints (lighter versions), I believe that the program is going to send back the medium color. Why didn't it just give me the hex for the tint? such as e5ebec? dunno - partly because it changes...LOL There is less blue in that tint...and it analyzed RGB
It's my thought that the blue edges out the green (by 2%) - and yes we have greenish-blue - but it is still blue.
TMI?