Skill: Color Grade (DaVinci Resolve)

Generate DaVinci Resolve node-based color corrections. Resolve uses a node graph instead of stacked effects - each node is an independent corrector with its own primaries, curves, qualifier (HSL Secondary), power windows, and LUT.

Node Order

Follow this professional node order for serial node chains. Each node serves one purpose:

1. •White Balance — Correct color temperature and tint first, before any other processing
2. •Exposure — Set overall exposure/gain to get correct brightness levels
3. •Main Conversion LUT — Apply camera-to-display transform (e.g., ARRI LogC to Rec.709)
4. •General Color Adjustments — Lift/Gamma/Gain wheels, contrast, color balance
5. •Color Saturation/Boost — Global and selective saturation adjustments
6. •Noise Reduction — Temporal and spatial NR (do this before sharpening)
7. •Black Levels — Crush or lift blacks, set floor
8. •Vignette — Power window with soft edge for light falloff
9. •Sharpening — Always last - sharpens the final result

Not every grade needs all 9 nodes. Skip nodes that aren't needed. For qualifier-based (HSL Secondary) corrections like skin fixes, insert additional nodes between steps 5 and 6 with the qualifier keyed to the target zone.

Resolve API Capabilities

The scripting API (Python/Lua, requires Resolve running) supports:

• •SetCDL({NodeIndex, Slope, Offset, Power, Saturation}) — ASC CDL values per node
• •SetLUT(nodeIndex, lutPath) — Apply .cube LUT to a specific node
• •ApplyGradeFromDRX(path, gradeMode) — Apply a saved grade still (DRX) to clips
• •ExportLUT(exportType, path) — Bake grade to .cube file
• •GrabStill() / ExportStills() — Save grades as DRX stills

Not available via API: Creating/adding nodes, setting color wheels directly, setting qualifiers/HSL keys, setting curves. These require either DRX files or manual work in the Color page.

Workflow

Option A: DRX Grade Stills (Full Node Graph)

If a DRX file is available (exported from Resolve with a reference grade):

1. •User creates reference grade manually in Resolve's Color page
2. •Export as DRX: Gallery → right-click still → Export → .drx
3. •Apply to all clips via script:

# apply_grade.py — run with Resolve open
import DaVinciResolveScript as dvr
resolve = dvr.scriptapp("Resolve")
project = resolve.GetProjectManager().GetCurrentProject()
timeline = project.GetCurrentTimeline()
clips = timeline.GetItemListInTrack("video", 1)
timeline.ApplyGradeFromDRX("/path/to/grade.drx", 0, clips)

Option B: CDL + LUT (Basic Corrections)

For grades that can be expressed as CDL values + a LUT:

1. •Analyze frames with analyze_frame.rb (same as Premiere workflow)
2. •Calculate CDL slope/offset/power from desired corrections
3. •Generate a Python script that applies CDL + LUT per node:

import DaVinciResolveScript as dvr
resolve = dvr.scriptapp("Resolve")
project = resolve.GetProjectManager().GetCurrentProject()
timeline = project.GetCurrentTimeline()
clips = timeline.GetItemListInTrack("video", 1)
for clip in clips:
    # Node 1: White Balance (via CDL offset)
    clip.SetCDL({"NodeIndex": "1", "Slope": "1.0 1.0 1.0", "Offset": "0.0 0.0 0.0", "Power": "1.0 1.0 1.0", "Saturation": "1.0"})
    # Node 3: Main LUT
    graph = clip.GetNodeGraph()
    graph.SetLUT(3, "AMIRA_Default_LogC2Rec709.cube")

Option C: Frame Analysis + Manual Guide

When API isn't sufficient (need qualifiers/HSL Secondary):

1. •Analyze frames with analyze_frame.rb to get HSV stats per zone
2. •Generate a detailed correction guide with specific values for the colorist:
   • •Per-node settings following the node order above
   • •Qualifier key ranges (hue center/range, sat center/range, lum center/range)
   • •Correction values for each keyed zone
3. •User applies manually in Resolve's Color page using the guide

Option D: Custom .cube LUT Generation (No Studio Required)

Generate targeted correction LUTs programmatically using generate_lut.rb. These work in both Resolve and Premiere with no API or Studio dependency.

# Remove warm amber/yellow cast from stage lighting
ruby generate_lut.rb yellow_fix /path/to/output.cube

# Roll off overexposed skin highlights (only affects lum > 70%)
ruby generate_lut.rb skin_highlight_fix /path/to/output.cube

# Adjust strength (0.0-1.0)
ruby generate_lut.rb yellow_fix /path/to/output.cube --strength=0.5

Available LUT types:

• •yellow_fix — Targets H=10°-60° (warm amber/yellow), reduces saturation 55%, shifts hue toward neutral. For stage lighting spill.
• •warm_skin_cast_fix — Fixes sunburnt/flushed red skin from warm practical lights. Shifts red skin hues toward peach. Only targets skin luminance+saturation range — leaves light sources, deck, and saturated objects alone.
• •overexposure_fix — Scene-wide ~1 stop reduction with highlight rolloff from 55%. For blown-out footage.
• •underexposure_fix — Scene-wide ~1.2 stop lift with shadow recovery and highlight protection. For dark footage.
• •black_crush — Crushes milky/lifted blacks below 12% luminance to true black.
• •skin_highlight_fix — Subtle skin-only rolloff above 70% luminance. For minor skin overexposure.

All LUTs support --strength=N (0.0-1.0) for intensity control.

Apply in Resolve: add node after conversion LUT → right-click → LUT → browse to .cube file. Apply in Premiere: Lumetri Color → Creative → Look dropdown → browse.

Scripting Setup (Windows)

RESOLVE_SCRIPT_API=C:\ProgramData\Blackmagic Design\DaVinci Resolve\Support\Developer\Scripting
RESOLVE_SCRIPT_LIB=E:\Davinci Resolve\fusionscript.dll
PYTHONPATH=%PYTHONPATH%;%RESOLVE_SCRIPT_API%\Modules\

Resolve must be running for scripts to connect.

Key Reference

CDL parameters map to Resolve's primary corrections:

• •Slope — Multiplier (like Gain). "1.0 1.0 1.0" = neutral. "1.2 1.0 0.9" = warmer
• •Offset — Added value (like Lift). "0.0 0.0 0.0" = neutral
• •Power — Gamma curve. "1.0 1.0 1.0" = neutral. Higher = brighter midtones
• •Saturation — Global sat. "1.0" = neutral. "0.0" = monochrome

Color Science Fundamentals

Key concepts for understanding what the LUT generator does and how to create new correction types:

Color Spaces

• •Rec.709 — Standard HD display color space. Small gamut, fixed gamma. What the audience sees.
• •Log curves (ARRI LogC, Sony S-Log3) — Logarithmic encodings that compress maximum dynamic range into a video signal. Look flat by design. Each camera manufacturer has their own curve.
• •ACES — Academy Color Encoding System. Scene-referred, open framework. Pipeline: Input Transform → ACES → RRT → ODT → Display. Future-proof, encompasses full human vision.

How LUTs Work

• •1D LUT — Per-channel curve (like Photoshop Curves). Can do brightness, gamma, contrast. No cross-channel interaction.
• •3D LUT — 3D lattice indexed by R, G, B simultaneously. Allows cross-channel operations (changing R output based on G and B input). A 33³ LUT has 35,937 sample points with trilinear/tetrahedral interpolation between them.
• •The .cube format is plain text: header + RGB triplets. Simple to generate programmatically.

HSL vs RGB for Corrections

• •Desaturating warm tones in HSL produces brown/sepia — this is a mathematical property. Orange desaturated = muddy brown.
• •RGB channel rebalancing (reduce R, boost B) cools warm tones toward neutral white — better for temperature correction.
• •Hue shifting (rotate in HSL) moves colors without losing vibrancy — best for "sunburnt skin → peach" type fixes.
• •Use luminance + saturation windows to isolate skin from light sources and saturated objects at similar hues.

Targeting Skin Specifically in a LUT

Skin tones occupy a narrow band: H=10-35°, S=0.10-0.45, L=0.25-0.75. Light sources, colored objects, and surfaces may overlap in hue but differ in saturation and luminance:

• •Light sources: very high luminance (>0.85) or very high saturation (>0.6)
• •Dark surfaces (deck/floor): low luminance (<0.20)
• •Skin: moderate saturation, mid luminance

Learning Resources

• •Color Correction Handbook by Alexis Van Hurkman — the industry-standard textbook
• •Blackmagic Official Training — free at blackmagicdesign.com/products/davinciresolve/training
• •Cullen Kelly (YouTube) — technically rigorous free color grading education, Netflix/HBO colorist
• •MixingLight.com — 1,200+ structured tutorials from working colorists (paid subscription)
• •Frame.io ACES Guide — blog.frame.io/2019/09/09/guide-to-aces/ — best ACES primer
• •Dado Valentic / Colour Training — colour.training — bridges color science research and practical grading
• •Kodak Color Theory Workbook — free PDF from Kodak covering fundamental color theory for motion pictures