This is a call for participation to a W3C Workshop on Wide Color Gamut (WCG) and High Dynamic Range (HDR) for the Web.

What is the purpose of this workshop?

The primary goal of the workshop is to bring together browser vendors, content creators, color scientists, and experts in other relevant areas (e.g. accessibility, scripting, security, web) to converge on technologies for enabling WCG and HDR on the Open Web Platform.

The secondary goals of the workshop are as follows:

  • To share experiences and strategies for color-correct rendering of images, video, 3D content and Web (HTML/SVG/CSS) content, on the Open Web Platform.
  • To identify roadblocks or built-in assumptions (such as 8 bits per component, RGB-only, SDR-only) which impede further progress.
  • To examine which scripting interfaces and APIs are needed for WCG and HDR support
  • To propose Web-compatible but future-proof extension mechanisms to enable WCG and HDR.
  • To share priorities from content creators, as to what features they need to develop compelling content.
  • To share strategies for adding HDR and mixed HDR/SDR content to a platform with emerging, inconsistently-deployed HDR support.
  • To examine Accessibility impacts of highly saturated colors and very high contrast ranges, and the exacerbation of observer metamerism by near-spectral primaries.
  • To plan a standardization roadmap (at W3C and at other SDOs) that maximizes the chance of sucessful, near to mid term deployment.

Which topics will be covered?

The following topics have been proposed, along with references to relevant specifications and documents. Please submit a pull request or raise an issue on GitHub to provide feedback and suggest further workshop topics. You may also email Chris Lilley <>.

Wide Color Gamut on the Web

  • WCG serialization and the CSS Object Model
  • A WCG-capable Color object for the CSS Typed Object Model
  • Canvas and WCG support
  • WCG and WebGPU
  • WCG authoring for progressive enhancement
  • Accessibility impacts of WCG
  • Potential and limitations of factory calibration of displays

Some relevant documents

  • CSS Color Module Level 4 adds color-managed WCG support, both RGB and CMYK, to CSS.
  • CSS Color Module Level 5 adds color mixing and color modification functions to CSS, using CIE LCH as the primary model.
  • Media Queries Level 5 enables conditional support based on color gamut and dynamic range capabilities
  • Media Capabilities allows media to be selected based on decoding,encoding and display capabilities
  • Canvas Color Space Proposal describes wide-color gamut and HDR support for canvas rendering contexts (2D, WebGL), WebGPU, and related APIs like ImageBitmap and ImageData.

High Dynamic Range on the Web

  • Detecting and using HDR support for video and for other Web content
  • HDR fallback and compatibility for SDR
  • Consuming HDR content in non-standard viewing conditions
  • Compositing HDR and SDR content
  • ICC profiles and HDR content
  • non-ICC color management approaches for HDR media
  • AVIF, a static and animated image format for HDR content
  • Accessibility impacts of HDR

Some relevant documents

WCG and HDR Standardization Landscape

Building on the previous topics, goal is to hold a plenary discussion on color standards on the Web:

  • Who is doing what: ongoing work across standardization organisations (SDO)
  • Standardization priorities and roadmap

Some relevant documents

How can I attend?

Attendance is free for all invited participants and is open to the public, whether or not W3C members.

Regitration opened on 15 January 2021. Please register for the event before 24 September 2021 to be notified of the videos availability, and of the logistics for the interactive sessions. The Program Committee will only accept participants whose registration data shows relevance to the topic of the workshop.

Our aim is to get a diversity of attendees from a variety of industries and communities, including:

  • Color Technology groups
  • Experts in verticals and delivery
  • Content owners and enabling technology providers (encoding and authoring tool makers)
  • Distributors and distribution enablers (e.g. CDNs)
  • Media devices manufacturers (monitors, TV sets, VR/AR headsets)
  • Browser vendors
  • Experts in relevant technologies (accessibility, color science, media, scripting, security, web)

This workshop, as other W3C meetings, operates under its Code of Ethics and Professional Conduct.

How can I suggest a presentation?

Talk submission has now closed To submit a talk for the workshop, please refer to our information for speakers.

What is W3C?

W3C is a voluntary standards consortium that convenes companies and communities to help structure productive discussions around existing and emerging technologies, and offers a Royalty-Free patent framework for Web Recommendations. We focus primarily on client-side (browser) technologies, and also have a mature history of vocabulary (or “ontology”) development. W3C develops work based on the priorities of our members and our community.


Program Committee


  • Chris Lilley, W3C


  • Chris Bai, BenQ. Co-chair of ICC Displays WG.
  • Dr. Phil Green, NTNU. ICC Technical Secretary.
  • Richard M. Adams II, Ryerson University
  • Mark Watson, Netflix
  • Pierre-Anthony Lemieux, MovieLabs