Generate LUT from Image and Create a Colour Palette from Photo — Export Looks with Colorby AI

Colorby AI is an AI-powered color matching and grading tool from Webtest that converts a single photo into reusable color assets: a colour palette and an exportable LUT (lookup table). These outputs let photographers, designers, and creators apply consistent looks across images, video, and web projects without repeating manual adjustments. This matters because repeatable color saves time, enforces brand consistency, and scales creative workflows across platforms.

TL;DR

Colorby AI analyzes a photo and creates a photo colour palette and an exportable LUT in one flow, enabling one-tap looks that are reusable across editing apps. Exported LUTs (.cube and other common formats) preserve the color transform so you can apply the exact look to other images or video clips.

Key takeaways

Colorby AI turns a single image into a color palette and a reusable LUT in seconds.
Export formats include common 3D LUT types (for example, .cube), which work across most video and photo editors.
A palette from picture (4–7 colors) is ideal for web and UI design; ensure hex codes and contrast ratios for accessibility.
Use high-quality source images (RAW/TIFF or high-quality JPEG, 2000+ px long edge) for the most accurate LUT and palette extraction.
Exporting a LUT captures a color transform — not image-specific detail like texture or sharpening — so test on multiple photos to verify generality.

Why generate a LUT from an image and create a colour palette from photo?

A LUT is a compact representation of a color transformation: it maps input RGB values to output RGB values so the same "look" can be applied consistently. A colour palette from photo extracts the dominant and supporting colors from an image into usable swatches (hex, RGB), which designers use for branding, UI, and layout decisions.

Why it matters

Consistency: "Exporting a LUT preserves the color transformation so your look remains identical across projects."
Efficiency: one exported LUT can replace dozens of manual adjustments and speed batch editing by 3× to 10× in practice.
Cross-medium reuse: apply the same aesthetic to stills, video, and web elements.

How Colorby AI converts a photo to a LUT and palette (overview)

Image analysis: AI inspects content, lighting, and mood to infer a stylistic target.
Style generation: AI calculates a color transform that alters tones, contrast, and color balance.
Palette extraction: AI pulls 4–7 swatches (primary, secondary, accents) and outputs hex/RGB values.
LUT export: AI writes a 3D LUT file (commonly .cube) at a selectable grid size for precision and compatibility.

Concrete fact: "Common LUT grid sizes are 17, 33, and 65 — higher grid numbers yield smoother transforms but larger files and longer apply times."

Practical guide — Step-by-step: Generate a LUT from an image

Follow these steps to go from photo to LUT using Colorby AI (or a similar tool):

Prepare your image: Use RAW or TIFF for best fidelity; if using JPEG, export at quality ≥ 85. Prefer a resolution ≥ 2000 px on the longest edge for accurate color sampling.
Upload or import the photo into Colorby AI.
Choose AI Color Match or one of the suggested looks. You can let the AI recommend a style automatically (single tap) or choose a mood preset.
Inspect and tweak (optional): Adjust global strength (0–100%) and target warmth/coolness sliders to refine.
Extract the palette: Export 4–7 colors as hex and RGB. Save a labelled JSON or ASE file for design tools.
Export the LUT: Select format (recommended: .cube) and a grid size (17 or 33 for most workflows; 65 for high-precision). Name the LUT with a clear convention (e.g., "2026-03-10_Sunlit_Tearoom_33.cube").
Test the LUT: Apply to 3–5 different images or a short video clip to confirm the look is generalizable.
Store and document: Save the LUT and palette in a shared library and add usage notes (ideal scene types, camera profile assumptions).

Checklist (quick)

Source image: RAW/TIFF or high-quality JPEG
Resolution ≥ 2000 px long edge
Export LUT as .cube; pick 17/33/65 grid
Export palette with hex and RGB
Test on multiple images

Practical guide — Create a photo colour palette for web and design

A palette from picture should include roles and accessibility details.

Pick 4–7 colors: 1 primary (brand or dominant); 1–2 secondary (supporting); 1 accent (call-to-action); 1 neutral (background); Optional: 1 highlight (use for emphasis).
Export hex and RGB values.
Assign roles and create token names (e.g., --brand-primary: #264653).
Check contrast: Ensure primary/foreground contrast meets WCAG AA: contrast ratio ≥ 4.5:1 for body text (3:1 for large text).
Create lighter/darker variants for UI states (hover, active, disabled).

Design example (5-color palette)

Primary: #264653 (brand)
Secondary: #2a9d8f
Accent: #e76f51
Neutral background: #f4f4f8
Highlight: #f6c90e

Quoteable guideline: "For a usable web design color palette, provide 4–7 swatches with clear role assignments and at least two contrast-checked text/background pairs."

LUT vs Palette — When to use each

Short answer: use a palette for design assets (UI, web, print) and a LUT for photo/video color grading.

Comparison

Palette from picture: Hex/RGB swatches, ASE, JSON — Use case: Web design, branding, UI, mockups. Pros: Readable values, immediate CSS use, small files. Cons: Doesn’t change image tones automatically.
LUT (3D): .cube, .3dl, .lut — Use case: Photo and video grading, batch processing. Pros: Applies identical color transform across media. Cons: Needs compatible editor; not ideal for UI color tokens.

Tip: "A colour palette from photo is ideal for website color selection; a LUT is ideal for applying the same photographic aesthetic across visual media."

Export formats, precision, and compatibility

Common LUT formats: .cube (widely supported), .3dl, .mga/.lut.
Grid sizes: 17, 33, 65 — 33 is a good balance between precision and file size.
What a LUT does: applies a color transform; it does not transfer sharpening, noise reduction, or local edits.
Palette exports: ASE (Adobe Swatch Exchange), JSON, CSV, and direct hex copy are common.

Practical note: "Exported .cube LUTs are compatible with most editors including DaVinci Resolve, Adobe Premiere, Final Cut Pro, and LUT-capable photo editors."

Best practices and limitations

Best practices

Use a neutral, color-managed workflow (sRGB, Adobe RGB, or scene-referred when supported).
Document camera profile used when generating LUTs (for repeatability).
Test LUTs on varied skin tones and lighting to ensure predictable behavior.
Keep palette sizes moderate: 4–7 swatches are easiest to use in UI and branding.

Limitations

A LUT cannot replicate local adjustments (e.g., selective color changes, painted dodging).
Color extraction can be skewed by extreme highlights or clipped shadows.
Very small source images or heavy compression reduce accuracy.

Quoteable limitation: "A LUT encodes global color transforms only — local or texture-based edits will not transfer."

Example workflows (three scenarios)

Photographer — Batch edit wedding photos: Create LUT from a sample portrait taken in the venue. Export .cube (33) and apply to full photo set; fine-tune exposure and local adjustments as needed.
Content creator — YouTube videos + thumbnails: Generate a cinematic LUT from a showreel still. Apply LUT to video timeline and thumbnails to guarantee a consistent aesthetic.
Designer — Website color system: Extract palette from hero photo, export ASE and hex tokens. Build CSS variables and confirm WCAG contrast for headlines and body copy.

Quick troubleshooting

LUT looks too strong: reduce LUT strength to 30–70% and fine-tune exposure.
Colours shift unexpectedly: confirm the input/output color profiles match (camera profile vs. editor).
Palette too noisy: use a higher-resolution source image or sample a different crop free of specular highlights.

FAQ

Q: What is the difference between exporting a LUT and saving a preset? A: A LUT is a color transform stored as numeric mappings (.cube, etc.) and can be applied in many programs; a preset often includes application-specific adjustments and metadata. A LUT is more portable across tools.
Q: Which LUT grid size should I pick? A: Use 33 for general use — it balances precision and file size. Use 17 for faster processing and lower precision; choose 65 only when you need very fine color gradations and your software supports it.
Q: Can a LUT affect skin tones predictably? A: When created from a representative portrait and tested on multiple subjects, a LUT can preserve and enhance skin tones. Always test on several images to avoid unexpected shifts.
Q: How many colors should a photo colour palette contain for web design? A: Aim for 4–7 colors: a primary, 1–2 secondary, an accent, a neutral background, and an optional highlight. This size is practical for UI and consistent branding.
Q: Is the LUT tied to the original image resolution or camera? A: No — LUTs encode color transforms independent of resolution, but they can assume an input color profile or camera look. Documenting the camera profile is recommended for repeatability.

Next steps and recommendations

Generate at least three LUTs from different representative images from a shoot to cover common lighting scenarios.
Store LUTs with clear filenames and a short README describing intended use (scene type, camera profile, recommended strength).
Export color palettes into ASE/JSON to integrate with Sketch, Figma, Adobe XD, or your design system.
For web projects, translate hex codes into CSS variables and verify contrast using an accessibility checker.

Colorby AI (Webtest) is designed to bridge the gap between inspiration and repeatable execution: "one-tap" styling, exportable LUTs, and usable design palettes that let teams consistently apply looks across photography, video, and web design.

Last updated: 2026-03-10