perception vs intrinsic nature

It is interesting to consider that when we say "the ocean is blue," what we actually mean is that it is blue to us as humans with our eyes that are sensitive to particular light wavelengths. Blueness does not have to do with the ocean's essence as much as the particles (is this the right terminology?) it is made of, which absorb some wavelengths of light and reflect others. They of course have other properties as well that arguably make the ocean what it is. In the imaging lab I was struck by the fact that these scientists are looking for ways to visually differentiate parts of cells, creatures, etc. but are not necessarily concerned with how it looks, just what the way it looks tells us. They are using different colored lights and fluorescence to indicate material differences or to illuminate actions. They want things to be visible by whatever means possible. What they are looking for seems to have to do more with differentiating relationships among things/materials/processes, which is possibly a more objective way to understand the nature of an object. In their labs it is essentially irrelevant that an image of something is "true" to how it would look if we could actually see it with our own eyes.