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Question on Chevreul item #76


lisanh1@...
 

I just got my book delivered today and read through Chapter One.  Maybe I'll find the answer further along, but I thought that I would ask anyway:  I am confused by a sentence in Chevreul's #76 in chapter one, on p. 12  second column first full paragraph where he states: "I will assume that orange is composed of red and yellow and that blue is composed of green and yellow,...."  I can't think of any additive or subtractive color or RGB, CMYK, or Lab color spaces that makes blue from green and yellow.  I know that any preschooler given finger paints makes green from blue and yellow.  Is Chevreul's statement an error or is there something to making blue from green and yellow from a different way of understanding?  Thanks.  
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Lisa Schofield


Dan Margulis
 


On Feb 27, 2020, at 9:00 PM, lisanh1@... wrote:

I just got my book delivered today and read through Chapter One.  Maybe I'll find the answer further along, but I thought that I would ask anyway:  I am confused by a sentence in Chevreul's #76 in chapter one, on p. 12  second column first full paragraph where he states: "I will assume that orange is composed of red and yellow and that blue is composed of green and yellow,...."  I can't think of any additive or subtractive color or RGB, CMYK, or Lab color spaces that makes blue from green and yellow.  I know that any preschooler given finger paints makes green from blue and yellow.  Is Chevreul's statement an error or is there something to making blue from green and yellow from a different way of understanding?  Thanks.  

Chevreul did not get it wrong, but I did. Somehow I inverted the words. It should read “that green is composed of blue and yellow.”

Congratulations, you get the first notation in the errata page we keep at 

Thanks very much for catching it!

Dan Margulis


Rex Waygood
 

Oh, I saw that and thought I could not be first………… :-)
Rex

On 29 Feb 2020, at 21:06, Dan Margulis via Groups.Io <dmargulis@...> wrote:


On Feb 27, 2020, at 9:00 PM, lisanh1@... wrote:

I just got my book delivered today and read through Chapter One.  Maybe I'll find the answer further along, but I thought that I would ask anyway:  I am confused by a sentence in Chevreul's #76 in chapter one, on p. 12  second column first full paragraph where he states: "I will assume that orange is composed of red and yellow and that blue is composed of green and yellow,...."  I can't think of any additive or subtractive color or RGB, CMYK, or Lab color spaces that makes blue from green and yellow.  I know that any preschooler given finger paints makes green from blue and yellow.  Is Chevreul's statement an error or is there something to making blue from green and yellow from a different way of understanding?  Thanks.  

Chevreul did not get it wrong, but I did. Somehow I inverted the words. It should read “that green is composed of blue and yellow.”

Congratulations, you get the first notation in the errata page we keep at 

Thanks very much for catching it!

Dan Margulis