The subject which I'm doing a mosaic of has very intense purples (violet cobalt manganese oxide pigments), but the only commercially available glass I can find with the color intensity of the object I'm trying to represent would be cobalt blue. So I've been hitting the color theory books and websites, trying to figure out placement or backgrounds that would make intense cobalt blue seem more like a shade of rich purple in context.
Here is an example Roman model boat of a cobalt blue glass in the British Museum from the first century. It's blue, but kind of purple as that glass often is. I like to think that 1900 years ago, someone served gravy from this.

While wading through all of the color theory information, I've come across some examples of how the human mind processes color and shape. Some of these examples involve motion, but many are just how the colors and shapes are processed.
For example, check out lilac chaser on Michael Bach's site.
This guy has collected several other visual phenomenon examples that are fascinating to me.
I'm leaning towards giving the cobalt blue a background of its inverse color in green. Given an unsaturated background of green, because of the way eyes process color with their red and green cones and rods, it should trick the mind into attributing more saturated red in the object done in cobalt blue (which is what I want, to play up the violet elements of the cobalt blue).
For example, check out lilac chaser on Michael Bach's site.
This guy has collected several other visual phenomenon examples that are fascinating to me.
I'm leaning towards giving the cobalt blue a background of its inverse color in green. Given an unsaturated background of green, because of the way eyes process color with their red and green cones and rods, it should trick the mind into attributing more saturated red in the object done in cobalt blue (which is what I want, to play up the violet elements of the cobalt blue).
What do you guys think?
Another thing that I discovered while pouring over glass chemistry was a complete surprise. Back in the 20th century, they used to make glass with uranium dioxide in it (completely radioactive). This sounds like a horrible cancer causing express train to legal liability, right? Well it turns out that glass is a great radiation shield, so this radioactive glass is not the deadly killer I first suspected it might be.


