Gradients of color are a grossly under-appreciated aspect of lighting design, wholly absent from the conversation of architectural lighting. This is historically the result of the traditional technologies available for electric lighting – all of which were too difficult to achieve subtle multi-channel control and optical placement of multiple zones of light from any single light source. There were some old-school solutions using dichroic glass filters with halogen sources (or even earlier techniques with dyed/stained glass on incandescent sources), but these were clunky and dangerously hot because of their subtractive filtering.
Yet frankly, gradients are ill considered in architecture because even natural lighting doesn’t convey gradients well into architectural spaces – for example, the aperture of windows is so small in comparison to a majestic sunset that the light entering the aperture is mixed into a blah homogenized white.
Only now with LED lighting do we have sources and optics small enough, efficiently generating primary colors of light and broad ranges of white, that such gradients could be achieved from compact fixture housings.
Looks like Mandalaki is using one large spherical optic to mix the multi-channels of LED, while keeping them distinct. I’m guessing inside they probably have a central color surrounding by a ring of the secondary color, plus a little diffusion.
In 2005, when Color Kinetics launched some of the first white-light cove lighting into the market, I helped design a new lobby entrance for CK’s corporate offices. We paired rows of RGB color changing cove lighting with white-CCT adjustable cove lighting, raking across a deeply textured Modular Arts surface, to create some beautiful color gradients. Doubly beautiful was when we added a row at the bottom of the wall firing upwards, tinting the shadows. It was a stunning effect, but in hindsight hardly anyone understood the sophistication available. Back in those days, it was so crazy expensive just to do LED lighting alone that offering dual rows of LED lighting for highly finessed design concepts wasn’t going to play well.