01 Scylla Chroma – The Scylla Universal Game Framework

The editor-only color workshop where Scylla palettes and gradients get built, audited, sampled out of existing images, and exchanged with the rest of a project’s color pipeline.

Summary

Scylla Chroma is the framework’s color authoring tool: a single Unity Editor window for building palettes and gradients, sampling colors out of images, running them through harmony, accessibility, mixer, compare, and recolor checks, and keeping every color asset in the project visible in a sidebar. Nine tabs share one active color and one library, so a color picked or sampled on any tab is immediately the color the others see.

The Scylla Chroma window with the Palette tab active and the library sidebar visible on the left.

Chroma is an Editor-only tool. It has no runtime DLL (Dynamic-Link Library), no build-size footprint, and no per-frame cost in a player build. The color types it reads and writes (ColorPalette, ColorGradient, ColorSwatchCollection) are runtime Scylla Core types, so the assets a project builds in Chroma are the same assets gameplay code loads at runtime. There’s no export step to “get colors out of the tool”; the tool is the editor for the asset.

The nine tabs are organized around the work, not around the data model. The first three (Color, Palette, Gradient) cover the everyday authoring loop. The next three (Image, Theory, Accessibility) are the analytical and generative tabs that feed into that loop. The last three (Mixer, Compare, Recolor) are smaller utility tabs that each solve one specific problem. A library sidebar runs down the left side of the window and surfaces every palette, gradient, and swatch collection asset in the project, with drag-drop into and out of the active tab.

Open Chroma from the Tools > Scylla > Utilities > Chroma… menu, or with Cmd/Ctrl+Shift+K. The first run lands on the Color tab with a default palette and gradient picked from the project (or an empty starter pair if the project has none).

Features

Color Editor tab. Provides four interchangeable 2D pickers (HSV Wheel, HSV Square, RGB Cube Slice, Oklch LCh Plane), channel sliders with Integer / Float input modes, a web-safe mode toggle that posterizes the pickers and snaps the active color to the 216-color palette, a hex field with copy/paste, a multi-space readout (sRGB (standard Red Green Blue), Linear, Oklch, HSL, CSS, Unity code, JSON), a screen eyedropper, color history, pinned favorites, and a named-color search field.
Palette Editor tab. Includes a swatch grid plus tabular list view, multi-select, batch operations, palette tags, optional semantic color roles, a stackable sort preview (hue / saturation / value / lightness / luminance / chroma / alpha / role / color name / ID, or a nearest-neighbor similarity walk), multi-color Copy Selected As (six text formats), and Remove Duplicates / Convert to Gradient actions.
Gradient Editor tab. Covers independent color and alpha rails, per-stop interpolation override (None, SmoothStep, SmootherStep, plus the 15 Penner easings), per-color-stop blend mode (Normal / Multiply / Screen / Add), three color spaces for the blend math (RGB, HSV, Oklab (a perceptual color space)), smooth or stepped mode, a non-destructive Reduction slider with Apply, and a Bake-to-texture dialog (PNG / TGA / EXR, sRGB or linear).
Image Sampler tab. Loads any texture, samples it with Point / Average / Gradient / Trace modes, and adds a magnifier overlay, arrow-key pixel nudging, and four extraction strategies: K-Means in Oklab, Median Cut, Luminance Buckets, and Most Saturated. Output can be saved as a palette asset or a gradient asset.
Theory tab. Offers a harmony generator (Complementary, Split-Complementary, Triadic, Tetradic, Square, Analogous, Monochromatic, Near-Complementary, Double Complementary, Rectangular) with a live hue-wheel diagram, Tints / Shades / Tones with an optional symmetric ramp, a seeded random palette with Oklab delta-E minimum, a material tone set (Shadow / Midtone / Highlight / Rim), a Planckian blackbody ramp, a jitter palette around a base color, and a multi-noise-driven palette.
Accessibility tab. Includes a WCAG (Web Content Accessibility Guidelines) 2.1 contrast checker with sample-text preview and AA / AAA badges, a color blindness simulator (8 types via the Vienot-Brettel-Mollon model), an Oklab delta-E calculator with descriptive labels, a named-color lookup across CSS Level 4 / X11 / RAL Classic / Chroma Colors, Correlated Color Temperature (CCT) via McCamy’s formula, and a palette statistics readout.
Mixer tab. Provides a two-color blend preview across sRGB, Linear RGB, Oklab, and HSV simultaneously, with a ratio slider and a double-click-to-add-to-palette shortcut.
Compare tab. Runs a side-by-side palette analysis, matching every entry in palette A to the nearest entry in palette B by Oklab delta-E, plus min / average / max delta-E summary stats. Useful when iterating a palette to make sure two versions stay close enough.
Texture Recolor tab. Texture remapping: source texture plus source palette plus target palette (same entry count) produces a new PNG where every pixel snaps to its nearest source-palette entry and is replaced with the corresponding target-palette entry.
Library sidebar. Provides three sub-tabs (Palettes / Gradients / Swatches), thumbnail previews, search/filter, a context menu (edit, rename, delete, open), drag-drop between the sidebar and the active tab, and live refresh when assets change on disk.
Preferences. Covers the default named-color database, checkerboard cell size, double-click-to-open toggle, and maintenance actions (clear color history, clear favorites). Lives at Edit > Preferences > Scylla > Chroma.
Project integration. Adds custom property drawers for ColorPaletteAsset and ColorGradientAsset with inline preview and “Open in Chroma” buttons. Double-clicking a palette or gradient asset in the Project window opens it in Chroma when the auto-open preference is enabled.
Import and Export. Palettes import from and export to ASE, GPL, Lospec JSON, and Chroma JSON, also import from ACT and plain hex lists, and also export to CSS variables and C# color constants. Gradients import from Chroma JSON and Photoshop .grd (both GRD3 and GRD5 formats, including foreground / background sentinels and multi-gradient library files), and export to Chroma JSON.

Tabs

Each tab has its own page in this set. The pages are usage-first: every panel, every right-click menu, every keyboard shortcut, every preference is documented in plain language, with screenshots where they help.

Authoring

Color Editor. The shared color picker: four 2D pickers, channel sliders, hex I/O, copy formats, history, favorites, eyedropper, named-color lookup.
Palette Editor. Swatch CRUD, tagging, sorting, multi-select, drag-drop, Remove Duplicates, Convert to Gradient.
Gradient Editor. Color stops, independent alpha rail, per-stop interpolation and blend modes, Reduction slider, Bake-to-texture dialog.

Sampling and generation

Image Sampler. Four sampling modes and four extraction strategies for pulling palettes and gradients out of textures and screenshots.
Theory. Harmonies, tints / shades / tones, random palettes, material tone sets, blackbody ramps, jitter palettes, noise-driven palettes.
Accessibility. WCAG contrast, color blindness simulation, Oklab delta-E, nearest named color, CCT, palette stats.

Smaller utility tabs

Mixer. Two-color blend preview across four color spaces.
Compare. Nearest-entry Oklab delta-E analysis between two palettes.
Texture Recolor. Palette-to-palette pixel remap on a source texture.

Infrastructure

Library. The sidebar’s three sub-tabs, search, drag-drop, live refresh.
Preferences. The full settings surface plus the persisted window state.
Import / Export. Every supported palette and gradient file format, with round-trip notes and known limitations.
Keyboard Shortcuts. One reference table for the whole window.

Getting started

Getting Started. Where the menu entry lives, the window tour, building a first palette and gradient, and where assets land in the project.

Where things live

The settings surface (named-color database, checkerboard size, double-click-to-open behavior, history / favorites maintenance) is documented on the Preferences page; the color asset directories live one level up at Project Settings > Scylla and are also covered there. The file format support and the Photoshop .grd notes live on the Import / Export page. The library sidebar’s behavior is shared across every tab and is documented once on the Library page.

Reference

Changelog. What shipped in each release, newest first.