# Liquid glass iridescence: parameters and references

Source: https://meniscus.site/effects/iridescence · Updated 2026-09-27

**Looks like:** View-dependent rainbow sheen like a soap bubble or oil film: hues shift with the angle and thickness, strongest near grazing edges, usually over clear glass.

Also called: thin film, holographic, oil slick, soap bubble, pearlescent, iridescent.

**Use in:** Decorative hero objects (orbs, AI/assistant spheres, badges, app-icon layers), selected hero states. Not for everyday chrome.

**Avoid:** Full-saturation rainbow fills on UI panels; iridescence behind body text; mixing it with heavy frost.

**Parameters:** film thickness 0.3–1.2 (normalised), strength 15–40 %, mostly in the outer half of the shape; animate slowly (8–20 s loops).

**Design tool:** Angular gradient (cyan → magenta → yellow → cyan) at 20–40 % in Overlay/Color Dodge, masked to the rim region; add a soft specular.

**Web:** CSS: conic-gradient overlay with mix-blend-mode: overlay masked to the edge ring. WebGL: thin-film cosine palette driven by the view/normal angle and noise.

**Shader:** `vec3 film = 0.5 + 0.5*cos(6.2831*(thickness*(1.0 - cosTheta) + vec3(0.0, 0.33, 0.67))); col = mix(col, col*film*1.4, strength * edgeFactor).`

## References

![A convex lens over a dark grid with soft colour glows, with a thin-film hue band on its rim.](https://meniscus.site/gallery/iridescence-dark-studio.webp)

## Use it with your assistant

This spec is what the Meniscus MCP server's `get_effect_spec` tool returns for `iridescence`. Materials, colours, light and composition rules that apply to every effect are in the [liquid glass guide](https://meniscus.site/liquid-glass). Connect: `claude mcp add --transport http meniscus https://meniscus.site/mcp` — setup for every client: https://meniscus.site/docs