Some of you may be aware that Natron has a histogram scope already builtin from day. I remember it from version 0.94. The histogram scopes are good in respect because it gives us a display of how the colors are spread across the SMH (Shadows, Mid-tones, and Highlights). And on top of that, it shows us the secondary and tertiary colors that are generated from the addition and subtraction of the RGB channels.
I am using the ColorLookUp node curves to demonstrate how the Histogram displays the colors from the image being process. You can tell where the color lie by the corresponding numbers in the curves editors and in the bottom of the histogram.
If you have any images that may have a certain color cast, you can load it with the ReadOIIO nodes and create the Histogram view. Any where along the Histogram’s SMH spectral grid should show this hue. One thing to remember that RGB Channels values (0 – 225, 0.0 – 1.0) are an additive in RGB color space. As each channels value gets higher, the colors gets brighter. Colors values gets darker in reverse. So it pays to have a 24bit and above monitor to be able to display these large range of colors.
I myself prefers the RGB Parade and Vectorscopes, but nonetheless the Histogram is still a very power scope to have and use.
P.S. Natron is 32bit Float processing. It would be more than helpful to read and understand float math I guessing.