What this project is about

Colour today must work across digital tools, physical materials, production processes, and changing lighting conditions.

This requires more than visual matching or proprietary colour books. It requires models that are calculable, comparable, and reproducible.

ARBE λ* is a framework that approaches colour not only as appearance, but as a balance of light, absorption, and reflection.

Why a new beginning was necessary

For many years, initiatives such as freieFarbe demonstrated that colour does not need to be locked into proprietary systems in order to function.

That work came to an end — but the underlying questions did not.

Today, colour workflows face new challenges:

• global supply chains,
• material diversity,
• metamerism,
• process consistency,
• and long-term reproducibility.

arbe-lambda-star.com continues this line of thinking where organisational structures stopped, with today’s scientific tools and questions.

The problem with current colour practice

Professional colour work still relies heavily on proprietary colour collections, medium-specific samples, and manufacturer-dependent systems.

As a result, colour systems are rarely compatible, conversions are limited or impossible, and colour decisions are often made “by eye”.

This approach is time-consuming, error-prone, and no longer adequate for modern, cross-disciplinary workflows.

Our approach

We focus on open, mathematically defined colour models, such as:

• CIELAB for perceptual colour description,
• RGB for digital systems,
• ARBE λ* as a physically grounded metric.

We believe the future lies in freely accessible, mathematically defined colour models such as CIELAB and RGB, complemented by physically grounded metrics like ARBE λ*, which describe colour not only perceptually but also in terms of light and energy.

Together, these models allow colour to be calculated instead of guessed, communicated instead of translated, and reproduced instead of approximated.

What ARBE λ* adds

ARBE λ* describes the energetic balance point of a colour — the wavelength at which absorption and reflection are in equilibrium.

This makes it possible to compare colours beyond appearance, analyse colour behaviour across materials, and understand why colours shift under different conditions.

ARBE λ* does not replace existing colour models. It extends them with a physical perspective.

What “open colour” means here

Open colour does not mean arbitrary colour.

It means openness instead of dependency, transparency instead of black boxes, and understanding instead of convention.

The computer is not a limitation for colour. It is its most precise tool.

Transparency note

arbe-lambda-star.com is an independent project. It is not a legal successor of any former association. It continues related ideas and principles independently and in a new scientific context.