Pixeltao CXA NES Palette

WHAT

A NES color palette that replicates the colors you see via the composite signal of a NTSC NES hooked to a Sony broadcasting video monitor.

This palette was not created using a mathematical conversion. Instead it was created using "methodical eyeballing". More info below.

HOW

I used all the power of modern retro gaming at my disposal: an A-Series Sony BVM, a MiSTer FPGA, an Everdrive N8 Pro, and a stock NTSC NES.

First, I calibrated the colors of the composite input of my BVM to match the RGB input (via the BKM-68X clone card) by displaying SMPTE color bars from the same source (using the SNES version of the 240p Test Suite).

Then to create the palette (using Sony CXA as a basis), I used "Palette Test by Loopy" and "240p Test Suite" both on MiSTer and on my stock NES to compare both sources on my BMV and make iterative micro adjustments until all colors became undistinguishable (or close enough in the case of some "impossible" colors).

ACCURACY

Due to a plethora of factors (NES console regions or versions, video amp circuit variations, TV decoders, user calibration), no RGB conversion of the composite video signal output by a NES can be 100% accurate. Even by using a scaler (like the RetroTINK) and a capture card, you don't get accurate colors because of the automatic clipping that occurs with some colors during the YIQ to RGB conversion.

The most obvious issue is that many of the brighter colors are out of range of the sRGB color space. A famous example is the "purplish blue" in Super Mario Bros. The composite video signal outputs it almost as neon-like royal blue that has a luminance and saturation so high that it falls outside of what you're able to display using standard RGB values. This results in the RGB conversion either looking washed out or the incorrect shade of blue. It also means that ALL of the screenshots of Super Mario Bros. you can find got the color of the sky wrong!

NOTE:

I also tested my stock NES on various CRT brands (including a JVC and a Panasonic), and without surprise, they all display different colors. So this palette is probably closer to how a Sony TV decodes and displays colors of the composite video signal.

SPECIAL THANKS

FirebrandX for all the work and information he put out there
Dan Mons for his studies on the NES palette
The unknown author who created the excellent Sony CXA NES color palette