scope:

This part of ISO 24505 provides a method for creating conspicuous colour combinations for use in visual signs and displays for people with colour deficiency and low vision. It is based on the method prescribed in ISO 24505:2016, but focuses on specific data concerning fundamental colours for people with visual disabilities. This part of document applies to the design of 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 part of the document addresses dichromatic colour vision of protanopia and deuteranopia as typical cases of colour deficiency. The other type of dichromatic colour vision called tritanopia and anomalous trichromatic colour vision (protanomalous, deuteranomalous and tritanomalous) are not covered in this part of the document owing to the lack of data.

Low vision includes various types of permanent conditions of reduced visual abilities that cannot be rectified by optical refractive correction, which mainly accompanies extremely low visual acuity or limited visual field, central or peripheral. This part 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.

This part, like the other parts, applies to the reflective or object-mode of colours, but may apply to the self-luminous-mode of colours if their colour coordinates are appropriately transferred to those of the object-mode of colours.

The selection of colours and their combinations toward the special use for safety comply with ISO 3864-1.