I realize "thing" is doing a lot of work in the above sentence, and that everything is all just particles. Still, I think there's something to the idea that form and shape are more real than color.
FWIW the "solid" object you're observing is mostly space and the "you can't pass through a solid object" as far as we know is just a probability not a certainty.
The point is eyes are extracting more information from the image.
Visible light interactions with the object exists in reality and capturing that information brings the image closer to reality, not further. It tells you more about the cubes properties.
As an extreme example, you might have a space documentary start by showing an image with a few stars, saying "it seems quiet", then showing the same image with a bunch of colourful gasses visible, saying 'but the reality is beyond what our eyes can perceive, in infrared the image is full of detail'.
Reality, actual reality and not our perception of it, is made up of every detail, the more of that information you can capture the closer to reality the image.