SonarAdvanced1fNoise

White noise is flat - equal energy at every frequency. The world is not like that, and neither are the images you actually want. SonarAdvanced1fNoise generates colored noise, where the frequency spectrum falls off as roughly 1/f^α: pink noise (α near 1) is soft and low-frequency-heavy, green sits in the middle, and negative exponents push energy up into the high frequencies. Swap the sampler's default white noise for one of these and the whole character of a generation shifts - dreamier compositions, different texture, less of that digital static look.

Mechanically it's FFT territory: generate white noise, transform it, shape the frequency spectrum by alpha, transform back. The alpha field is the exponent - the tooltip puts it plainly: positive values increase low frequencies (with colorful effects), negative values increase high frequencies. vertical_factor and horizontal_factor scale frequency separately per axis, which is how you get noise that behaves differently top-to-bottom than left-to-right. k is... a knob. The author's own tooltip says there's no description of exactly what it does, it's just another knob to turn for a different effect. That's refreshingly honest, and worth internalizing about the whole pack: these nodes are a toybox, and half the fun is turning knobs you don't fully understand.

The inputs you'll actually set as a beginner: alpha (start around 0.25–1.0 and move it), factor (scaling strength), and maybe horizontal_factor/vertical_factor when you want directional noise. The use_sqrt toggle controls whether the FFT divides with a square root; the tooltip warns negative hfac/wfac don't work when it's enabled, and turning it off makes the parameters hit much harder. rescale is the pack-wide feature: set it non-zero and this item plus everything chained into it scale their factors to add up to that value - a clean way to keep a blend at constant total strength.

Output is SONAR_CUSTOM_NOISE, and the optional sonar_custom_noise_opt input lets you chain further noise items onto the same wire. From there you plug the chain into a Sonar sampler, NoisyLatentLike, or SamplerConfigOverride - wherever a custom noise input is accepted - and it overrides the node's selected noise type.

Install is the one-liner:

cd ComfyUI/custom_nodes
git clone https://github.com/blepping/ComfyUI-sonar

No model downloads, just a restart.

One caveat the author puts in the repo's errata and it applies here more than anywhere: the noise names are best-effort. What blepping calls "pink" may not be textbook pink noise. Judge by eye, not by the label. And the standard sonar gotcha stands - generation is explicitly not reproducible across versions, so log your git revision if a result matters to you. If you want a specific flavor of colored noise, this is the fastest way to get it; just don't over-index on the name.