Philosophy 100, Fall 2006					

Color Handout 2



An argument against (DT) based on the shy chameleon:

	1.	If (DT) is true, then the shy chameleon is red when no one is looking at 
		it.

	2.	The shy chameleon is not red when no one is looking at it.

	3.	Therefore, (DT) is false.
	
	

Definition: An object's Spectral Surface Reflectance (SSR) specifies, for each wavelength of light, what percentage of the light of that wavelength that hits the object gets reflected.


The SSR theory of color (SSR):


	* 	The property of being green is identical to the property of having a 
		certain kind of SSR.

		("Very roughly...the kind of SSR that allows an object in normal 
		illumination to reflect significantly more light in the middle 
		wavelength part of the spectrum than in the long wavelength part, and 
		approximately the same amount of light in the short wavelength part as 
		in the rest.")

	*	The property of being red is identical to the property of having another 
		kind of SSR.

	*	etc.



An Argument Against (SSR) based on the existence of metamers?


	1.	An object emitting light of wavelengths 540nm and 670nm is yellow.

	2.	If (SSR) is true, then an object emitting light of wavelengths 540nm and 
		670nm is not yellow.

	3.	Therefore, (SSR) is false.
	
	
	
Definition: C is a unitary color =df. C is not a perceptual mixture of two colors.

Definition: C is a binary color =df. C is a perceptual mixture of two colors.



The souped-up argument from variation:


This argument is based on the following scenario:

	
	Joe and Bob are normal observers, looking at a paint chip under standard
	conditions. The chip appears to be unitary red to Joe. The chip appears
	to be slightly bluish-red to Bob.



	1.	Either Joe or Bob fails to correctly perceive the chip's color.

	2.	If either Joe or Bob fails to correctly perceive the chip's color, then 
		both Joe and Bob fail to correctly perceive the chip's color.

	3.	If both Joe and Bob fail to correctly perceive the chip's 
		color, then no one ever correctly perceives the color of anything that 
		exists outside the mind.

	4.	Therefore, no one ever correctly perceives the color of anything that 
		exists outside the mind.