Stanley Gibbons colours - Blue or Ultramarine?

[Aaron J]

I've been pondering over this for a while. How can I tell if a stamp is blue or ultramarine?

I don't have the colour guide issued by Stanley Gibbons, and I've tried to compare my stamps online, but it's not just blue and ultramarine, but other shades of the same colour-shade-spectrum-thing.

For example, I have a couple of blue 1d Queen Elizabeth II stamps of the Wilding variety, I'm not able to distinguish watermarks as I don't have the kit, but SG 516 says ultramarine, and SG 541 and SG 571 are listed blue.

Is there any significant difference in the shade that I may pick up on with a scanner or magnifying glass or reference to an online Stanley Gibbons colour guide?

I also come across difficulty with reds and red-browns. If I knew for certain which stamp is which, then it'd be easier to refer to them for colour and shade differences and go by them... but I don't.

Any help on this would be gratefully appreciated!

Thank you!

[Admin Bear]

well as a person with partial color blindness i can relate to your frustration. i have discovered (through some amazing guidance here) that you should NEVER trust your computer screen with colors.

Every scanner is different and every screen is slightly unique in how it displays colors.

i have found that reading a description of 2 colors and then having some copies to compare may help from time to time. for example with your Blue versus Ultra marine question.

1st off they are both a type of blue and the difference lies in the red spectrum (ironically my weak area). to differentiate the two i take multiple copies of a stamp and look for large variances.. Blue as Blue is vibrant, clear, and bright where Ultra marine is more dull and rather lack luster.

if we look at the US Colombian issues as an example the Blue stamps are rather hard to find but when you see one in person you will not question how much brighter it appears.

[MikeC99]

Aaron J, I am also somewhat colour blind so I have difficulty distinguishing many shades of colour. Here are the colours from my SG Stamp Colour key that you are wondering about.