This job called for a color gradient on a white background; sounds easy enough, but getting that right degree of gradation requires a bit of tweaking between lens choice, shooting stop, camera to subject to background distance, and then the light and color.
So in this setup I used an 85mm lens, lit to an T8, and fired 3 x 2k fresnels with Hampshire frost at a white cyc. After that the grips rolled out a 20’ colored gel across a goal-posted pipe to allow easy adjustability of where the gradient was on the wall as well as how hard or soft an edge we liked.
The right smoothness came from shooting a T5.6, so we ND’d the lens and had the perfect result.
To darken the blue, top double and single scrims were employed- ND gels could also be stretched across the goalpost as another option.