Color accuracy in Stagehand

Stagehand color data comes from manufacturer ‘best guess’ representations of their colors on a computer screen, and have been adjusted to most accurately reflect colors on iPhone screens at full brightness. Stagehand is not able to fully accurately show gel colors, as gel and computer screens work in fundamentally different ways when it comes to producing visible color. This difference is the difference between additive and subtractive color mixing.

In an additive color mixing system, like a computer screen, multiple ‘primary’ colors, in our case Red, Green, and Blue, are used at varying brightnesses to create the illusion of millions of different colors.

In a subtractive color mixing system, like a stage light with gel, ‘full spectrum’ light (meaning all colors in the visible spectrum are present) is shone through a colored piece of heat-resistant material, blocking parts of the spectrum from passing through, reflecting them back into the fixture and eventually creating heat, resulting in only some colors coming through the color filter.

While this simplifies much of the physics behind what is happening, it provides a basic example of why gel and computer screens are so different, and why the representation of a color on a screen can not currently match the color you will see on stage.

All color data in the current version of Stagehand is stored only in RGB (inside the bounds of the sRGB color space), and then HSB is calculated on the fly from that value. This conversion makes in unsurprising that other products may have different values for the color. Additionally, those RGB colors were designed to emulate the color on a screen. Some products have color profiles for different fixtures in order to calculate a more accurate set of color values for a specific product (for example, ETC’s Eos family of consoles does this).

Both the RGB and HSB are designed to give you a close approximation to the gel color, allowing you to tweak color from there. We recommend using the HSB values when first creating color presets, and then fine-tuning them to work for the situation and to match across different fixtures with different output profiles.