Chapter 4: Accessibility

Created by Sarah Choi (prompt writer using ChatGPT)

Accessibility (Color‑Blind Safe Sets) for Character Concept Artists

Why Accessibility Belongs in Color, Pattern & Livery

Accessibility is not a post‑processing filter; it is a design constraint that improves clarity for everyone. When you build palettes, patterns, numbering, and trim levels with color‑vision diversity in mind, identification becomes faster, combat reads become safer, and livery communicates faction identity without relying on fragile hue differences. This article bridges concept and production concerns so your decisions survive camera distance, motion blur, and shader stacking—while remaining welcoming to players with Deuteran (green‑weak), Protan (red‑weak), and Tritan (blue‑weak) color‑vision deficiencies (CVD).

Understanding CVD Without Turning Artists into Optometrists

Color‑vision deficiencies primarily reduce hue separation along specific axes. Deuteranopia and protanopia collapse red↔green differences; tritanopia collapses blue↔yellow. In practice, reds can read as brown or dark gold, greens drift toward ochres, and blues and purples merge. Pure hue shifts alone are unreliable; value (lightness), saturation (chroma), and pattern/shape become the backbone of your livery grammar. Designing for CVD means building redundancy: when hue fails, value and shape still carry the message.

Palette Engineering That Survives CVD

Start by defining your palette in four functional slots—base, accent, signal, and neutral—then give each slot at least one CVD‑safe alternate. Favor pairings with strong lightness contrast and divergent perceived warmth. Blue‑leaning cyans against warm ochres, deep indigos against pale creams, and violets against desaturated yellows survive most simulations. Avoid relying on red vs. green alone for team IDs; pair a warm red with a cool slate or a dark teal with a light sand. On paper, target a lightness delta of roughly 30–40 L* between primary opposing fields and ensure accents beat nearby materials by 15–20 L* so piping and edge bands remain visible under bloom and fog. In shaders, expose the palette slots so accessibility presets can swap to alternates at runtime without authoring new textures.

Patterns and Shape: The Redundancy Multiplier

Patterns are your insurance policy when chroma collapses. Assign team or role via distinctive, low‑frequency shapes that won’t moiré: broad chevrons, sash bands, sashiko‑style stitch fields, or segmented armbands. Striping should be thick, broken, or angled to avoid mipmap shimmer. Reserve a unique silhouette‑level motif per faction—a crown stripe, an angled hip band, a triangular cape bite—so faction identity persists even in grayscale. For role icons, couple color with form: a cross for medics, a cog for engineers, an arrowhead for scouts. Treat these icons as decals or vector masks, not baked pixels, so they survive scaling and can be recolored by accessibility modes.

Numbering, Typography, and Iconography That Read in Grayscale

Numbers and letters should communicate rank and identity irrespective of hue. Choose typefaces with open apertures and differentiated glyphs (0/8, 1/I/l) and maintain generous stroke widths that survive TAA. Outline or drop‑shadow critical marks against busy materials, but keep outlines narrow enough to avoid halation. For iconography, prefer simple, asymmetric silhouettes and avoid relying on interior color fills to differentiate roles. If two role badges must share shape families, alter edge logic (rounded vs. notched) or include a distinctive micro‑pattern fill.

Trim Levels Without Exclusion

Cosmetic ladders often increase saturation and metallicity, which can destroy contrast for CVD. When you ladder Base → Veteran → Elite, add readability, not just spectacle. Promote contrast through material and value rather than solely through chroma: matte vs. gloss, brushed vs. polished, dark inlay against light substrate. Cap reflective area percentages so specular spikes don’t erase piping or unit numbers. Provide an accessibility variant of each elite trim that preserves the prestige motif while boosting lightness separation—for instance, swapping a red‑gold filigree to a deep umber + pale brass pairing that survives red‑green collapse.

Faction Identity That Survives Simulation

Define each faction by a trio of traits—shape language, value envelope, and signal strategy—so identity persists under color‑blind simulation. A militarist faction might live in mid‑dark values with hard‑edged chevrons and high‑lightness signal panels; a mystic order might favor high‑dark contrast robes with iridescent which shift to value‑stable edge cording under accessibility mode. Test identity by rendering each faction in grayscale and under deuteran/protan/tritan simulations; if you can still tell them apart at a distance, your system is robust.

Camera, Motion, and Biome Stress Testing

Accessibility fails most often under real gameplay stress: distant LODs, motion blur, fog volumes, and bloom. Bake a test scene with your common biomes (snow, desert, forest, neon city) and your harshest post‑FX. Check mid‑shots and long shots for livery collapse. If two factions fuse in the snow, raise value contrast or flip signal slots (e.g., move from pale armband to dark cuff). If sprint blur erases stripes, widen bands and reduce frequency. Use a small LUT per faction that protects the contrast relationship in night or sandstorm conditions.

Production Hooks: Making It Real in Engine

From the start, design your livery packet for parameterization. Mask base, accent, and signal into discrete channels so design can be swapped at runtime. Provide an accessibility preset per faction that remaps hues and nudges values while keeping the same motifs and icons. Keep role badges and numbers as decals or vector glyph sheets so UI and localization can drive them. Document minimum stroke widths for numerals at far LOD, safe zones away from high‑deformation areas, and naming that groups all accessibility assets alongside the base skin to prevent SKU sprawl.

Authoring Workflow for Concept and Production

In concept, present every character with a normal palette and an accessibility alternate on the same sheet; this prevents visual surprises later. Include a small grayscale swatch bar and simulated CVD thumbnails of the full‑body paint. In production, wire a debug toggle that cycles through grayscale, deuteran, protan, and tritan approximations, plus a value‑only view, so artists can iterate without external tools. During review gates, require a pass where faction identity, role icon, and unit number are correctly identified at two distances while under simulation.

Practical, CVD‑Resilient Palette Suggestions (with alternates)

Favor pairs that separate primarily by value and secondarily by temperature:

  • Deep indigo (#26356D) with pale sand (#E8D9B5) and a signal cyan (#39A9DB) → Alternate signal: vivid violet (#7A5DC7).
  • Charcoal slate (#2E3138) with warm bone (#E6E1D6) and hazard saffron (#E3A01A) → Alternate signal: cool teal (#2FA6A0).
  • Forest teal (#205E5D) with light limestone (#EAE6DA) and royal purple (#5B3C99) → Alternate signal: clean white (#FFFFFF) piping.

These sets maintain clear lightness steps and temperature divergence even when red‑green or blue‑yellow distinctions are dampened. Always pilot them through your post‑FX to confirm.

Documentation That Downstream Teams Will Use

Package your accessibility thinking so others can ship it. Provide palette chips with L* values, a swatch page showing normal and accessibility alternates, icon and numeral sheets with minimum sizes, and placement orthos with accessibility annotations (e.g., “role badge must touch a high‑contrast field”). Include a one‑page “faction contrast contract” stating the value ranges for base, accent, and signal slots so marketing and skins teams don’t erode clarity across seasons.

Testing and Acceptance Criteria

Define simple, objective checks. In a side‑by‑side panel with CVD simulations, a reviewer should correctly call (1) faction, (2) role, and (3) unit number within two seconds at gameplay distance. Numbers must remain readable at far LOD; role icons must remain discriminable under motion blur; and faction motifs must remain distinct in grayscale. Maintain a legibility floor for wear and grime so ageing never erases identifiers.

Common Pitfalls and How to Avoid Them

The most frequent failure is designing prestige skins that sacrifice contrast for spectacle—gold filigree on crimson reads as a single band to red‑weak players. Another is treating accessibility as a copy of UI standards without testing it in motion; livery is 3D, deforming, and reflective. Finally, beware over‑tight patterns that shimmer; fewer, bolder bands often outperform intricate micro‑prints. When in doubt, reduce frequency, increase value separation, and back up hue with shape.

Closing: Accessibility as a Style Choice

When accessibility becomes part of your faction grammar, your world feels intentional: readable at a glance, iconic at distance, and inviting to a wider audience. Color‑blind safe sets aren’t compromises; they are clarity delivered through palette discipline, pattern hierarchy, and thoughtful material choices. Build your alternates upfront, ship them in your packet, and protect them in reviews—your players will feel the difference, even if they can’t name it.