BS ISO 24505-2:2025 PDF

1 Scope This document provides a method for creating conspicuous colour combinations for use in visual signs and displays in which multiple colours are used in various combinations to make them visible and conspicuous to people with colour deficiencies and low vision. This document addresses protanopia and deuteranopia of dichromatic colour vision as typical cases of colour deficiency. This document does not cover tritanopia (another type of dichromatic colour vision) and anomalous trichromatic colour vision (protanomalous, deuteranomalous and tritanomalous) due to a lack of data. This document covers low vision caused by various types of eye diseases, such as retinitis pigmentosa, macular degeneration, glaucoma, cataract, and others. It does not cover amblyopia, which also brings extremely low visual acuity but is classified differently in the medical field. NOTE     "Low vision" includes various types of permanent conditions of reduced visual abilities that cannot be rectified by optical refractive correction, and that are accompanied by extremely low visual acuity or limited visual field, central or peripheral. This document applies to the reflective or object-mode of colours, but can apply to the self-luminous-mode of colours if their colour coordinates are appropriately transferred to those of the object-mode of colours.