Evolution of human colour vision lights, which appear to be clear. Other colour perception issues include having trouble distinguishing yellows from reds and violet, lavender and purple from blue. In other cases, objects that reflect both red and blue light may appear to just be blue to these individuals. Deuteranopes, who are missing medium wavelength sensitive cones, are similar to protanopes in that they cannot distinguish between colours in the green-yellow-red part of the electromagnetic spectrum. However, deuteranopes do not suffer from dimming issues. For example, purple colors are not seen as being opposite to other colours in the spectrum but instead appear to be
The Colour Out of Space of his stylistically and conceptually finest short stories." Joshi praises the work as one of Lovecraft's best and most frightening, particularly for the vagueness of the description of the story's eponymous horror. He also lauded the work as Lovecraft's most successful attempt to create something entirely outside of the human experience, as the creature's motive (if any) is unknown and it is impossible to discern whether or not the "colour" is emotional, moral, or even conscious. His only criticism is that it is "just a little too long". The text of "The Colour Out of Space", like many of Lovecraft's