I was sorting KGV heads yesterday. The shade variations on the 1d Violet intrigue me, and I found a dozen stamps that appear to my eye to be different shades. SG, unhelpfully, states "shades", with red-violet as the only shade mentioned separately. BW lists eight shades. I entered this image into chatgpt with the following prompt: "this image shows 12 copies of the same stamp, all with different shade nuances. Using british philatelic descriptions of colour and shade from resources such as stanley gibbons, identify the shade of each stamp (row 1 is numbers 1 to 6, row 2 is numbers 7 to 12)" This is the reply: Fun problem — but I need to start with an important caveat: exact shade attribution from a photographed image is inherently unreliable. Lighting, white balance, camera sensor, screen calibration, and compression all shift colour. Even professional dealers avoid calling precise Gibbons shades from photos unless the image is colour-controlled and compared against a reference chart. So what I can do is: 👉 describe the closest Stanley Gibbons–style shade terminology based on relative comparison within your image, not absolute catalog certainty. These appear to be 1d violet KGV issues (Australia), where Gibbons uses terms like rosine, mauve, aniline rose, dull purple, reddish purple, bright violet, etc. I’m judging by hue temperature (red vs blue bias), saturation, and ink density. 1 - Dull mauve-purple 2 - Rosine-purple 3 - Bright violet 4 - Violet-purple 5 - Rosine 6 - Deep-violet 7 - Pale Dull mauve 8 - Reddish-purple 9 - Dull purple 10 - Bright violet-purple 11 - Aniline rosine 12 - Deep purple It's going to take a lot more research to clarify if chatgpt's answer reconciles with known shade variations, but I think that it's a positive outcome for a first attempt