# Curves (RGB)

> The most expressive tool in Darkroom — shape brightness, contrast, fades, and film-like color tone by bending a single line per channel.

Source: https://darkroom.co/help/edit/curves-rgb
Section: Edit
Updated: 2026-06-10

Curves is the closest thing Darkroom has to a blank canvas. With it you can fix exposure, build contrast exactly where you want it, lift blacks into a soft fade, and tune color tone region by region. It's powerful enough that you can recreate most popular film and filter looks with this one tool — which is exactly why it became the foundation Darkroom was built around.

A simple mental model helps: every pixel is three buckets of light — red, green, and blue. Curves sorts your photo into tonal regions (blacks, shadows, midtones, highlights, whites) and lets you add or drain light from those buckets *within each region*. Pick a channel from the selector on the left — **RGB** moves all three buckets at once (brightness and contrast); **Red**, **Green**, and **Blue** move one at a time (color and tone). You'll find Curves in the Edit view toolbar.

![The Curves editor in Darkroom with the tone regions and channel selector](https://darkroom.co/assets/images/posts/2019-histogram-curves.jpeg)

*Curves divides the image into tonal regions; each point you move remaps how those input tones come out.*

## The RGB curve: selective brightness and contrast

The RGB curve controls the amount of light in your photo — but unlike the Brightness slider, it lets you do it *selectively*, one tonal region at a time. That's the whole point. Brighten a dark landscape foreground by pulling up only the shadows and midtones, and your clouds keep all their detail instead of blowing out.

Two shapes do most of the work:

- **A bow** (up or down) raises or lowers brightness across the regions you bend. Bow the shadows up to open them; bow the highlights down to rein them in.
- **An S-curve** adds contrast: lift the highlights, drop the shadows, and the image gains punch while the midtones hold. Flatten it instead to soften a harsh photo.

Pull a region all the way up and it goes white; all the way down and it goes black — handy for crushing shadows into a silhouette or washing out highlights to focus attention. Keep an eye on the [Histogram](/help/edit/histogram) so you don't clip more than you mean to.

## Per-channel curves: color and film tone

The Red, Green, and Blue channels are where personal style lives. Adjusting them in different regions gives a photo a two-tone cast — say, slightly more red in the shadows and a touch less in the highlights — which is precisely how film stocks earned their signature looks. A film that was more sensitive to green in low light gave shadows a green cast; pull the green channel up in the shadows and you've recreated it.

The trick is restraint and coordination. Color curves usually move *together*: to build a contrasty, toned look, give all three an S-curve and let the small differences between them create the tone. Big moves on a single channel contaminate neutrals and skin, so make small adjustments — tapping just above or below the curve nudges it 1% at a time for fine control.

## Fades

A fade is just a curve move: lift the blacks toward gray and drop the whites toward gray. The result is the soft, airy look that defined the Instagram and VSCO era — and because it crushes nearby values together, it also simplifies detail and pulls the eye toward your focal point. Push it gently for a whisper of softness, or hard for a bold, washed-out style. Bias the channels differently and your fade picks up color: warmer highlights, cooler shadows.

## A useful habit

When an edit starts looking strange and you can't tell which channel is causing it, long-press the channel selector to toggle that single curve off while keeping everything else in place. It's the fastest way to isolate what a curve is actually doing.

Curves works best early, before finishing effects, and pairs naturally with [Color Grading](/help/edit/color-grading) for stylistic color — then save the whole thing as a [preset](/help/edit/presets) to reuse it.

## Related

- [Histogram](/help/edit/histogram) to watch clipping while you work
- [Color (HSL)](/help/edit/color-hsl) for targeted, per-color fixes
- [Using Curves, Part 1](/blog/2015-06-curves-part-1-of-2) — brightness and contrast in depth
- [Using Curves, Part 2](/blog/2015-07-curves-part-2-of-2) — color, tone, and film emulation