The base color of a material in unlit mode changes when specular amount is above 0.0

Material's RGB base color values are changed in Unlit mode when specular is greater than 0. 

User repro video: 

[Link Removed]

Tested in: 4.23.1 CL#9631420, 4.25 CL#11574810

1. Create a new material of any base color and a specular of 0.
2. Create a second material with the exact same base color and a specular greater than 0.
3. Change the View Mode for the second material to unlit.
4. Using a RGB color picker to test, you can compare the base color values.

Result: the values of the base color on the second material are changed when adding specular in Unlit view mode.

Expected: The base color to not be affected.  

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