The Second Lightest Color

[Mehmet Saygın]

I have asked this question, but the topic was pulled to a different side which is human color perception. Because of this reason, I did not get a satisfactory answer. I want to ask again the same question more clearly ,taking refuge in your understanding. Thanks in advance. 

If we think about all possible color hues according to "Lab Color Space" (lightness values)L* and these colors are saturated ( pure hues without lighter shades ), yellow is the second lightest color next to white and it is also the closest color to white. ( I mean here the lightness, not brightness. If we are talking about the brightness, lime green is perceived by human eye as a brighter color than white, because our cones are most sensitive at the 550 nm wavelength.) How can this situation be explained physically ?

Edited April 11, 2018 by Mehmet Saygın

[Hasan Özel]

On 11.04.2018 at 7:09 PM, Mehmet Saygın said:

I have asked this question, but the topic was pulled to a different side which is human color perception. Because of this reason, I did not get a satisfactory answer. I want to ask again the same question more clearly ,taking refuge in your understanding. Thanks in advance. 

If we think about all possible color hues according to "Lab Color Space" (lightness values)L* and these colors are saturated ( pure hues without lighter shades ), yellow is the second lightest color next to white and it is also the closest color to white. ( I mean here the lightness, not brightness. If we are talking about the brightness, lime green is perceived by human eye as a brighter color than white, because our cones are most sensitive at the 550 nm wavelength.) How can this situation be explained physically ?

Let's approach your question scientifically,

Why is white is the lightest color ? The answer is simple, because white objects reflect the most amount of visible light in all other colored objects. Lightness parameter is related to light reflectance of objects. If we turn back to your problem, yellow is the second lightest color next to white and it is also closest color to white. The reason of this is the light reflectance parameter. If we are talking about pure hues without lighter or darker shades, yellow colored object reflects the most amount of incoming lights, but you should be careful about this is only acceptable for pure hues. If your color reference does not include pure hues, this is not valid (i.e lighter shades of blue can be lighter than darker shades of yellow.)

I add a link for more detailed information :

https://www.sciencedirect.com/science/article/pii/S0307904X06001211 

[John Cuthber]

I suspect this thread will be closed soon.

In the meantime, why not try to define "lightest" and "colour".

Without that clarification you are going to get no science.

[koti]

16 minutes ago, John Cuthber said:

I suspect this thread will be closed soon.

In the meantime, why not try to define "lightest" and "colour".

Without that clarification you are going to get no science.

This time the OP narrowed down the question to Lab color space so there is an answer. Considering the last threads fiasco, I’ll let other users tackle this one. 

[Bender]

A possible explanation could be that yellow is really light brown, so you are comparing red, blue, green... and light brown. If we would compare brown, blue, green...  and light red, the lightest colour would be light red.