We know redness or sweetness when we see it.

This is not intended as a criticism. But it sometimes seems to me the philosophical practice of choosing simple examples of a concept often strips away all hope of learning something about the concept from the example.

For example, it the above had been written "We know puceness or umaminess when we see it", we might have some hope of connecting the concept of perceiving the qualia with the concept of learning the name of the qualia.