Color task

Color tasks are tasks that involve the recognition of colors. Color tasks can be classified according to how the color is interpreted. Cole describes four categories of color tasks:

Earlier classification of color tasks did not attempt to be comprehensive, and mainly differentiated between color matching/ordering, pseudoisochromatic plates and color-naming. In Cole's definitions, the latter would be denotative color tasks and the others would be comparative color tasks.

Color blindness (or color vision deficiency) is a defect of normal color vision. Because color blindness is a symptom of several genetic and acquired conditions, the severity can range drastically from monochromacy (no color vision) to anomalous trichromacy (can be as mild as being indistinguishable from normal color vision). Congenital (genetic) color blindness causes difficulty in all four kinds of color tasks. However, cerebral color blindness may cause issues only in some types of color tasks, and other conditions that do not affect color vision can still affect color vision tasks (e.g. anomia).

Comparative color tasks require a subject to differentiate two colors. Simple examples include many color vision tests, which are specifically modeled as comparative tasks. For example, the Ishihara test and other pseudoisochromatic plates require a direct comparison (and therefore discrimination) of foreground and background colors to be able to read the embedded number/character.

Arrangement tests such as the Farnsworth D-15 also requires comparison of adjacent colors to be able to arrange them in a meaningful spectrum. In addition to being able to distinguish two colors, arrangement tests also require measuring color difference and decision making based on this parameter. Despite the increased complexity of this task, they were not differentiated by Cole, though were by others.

Comparative tasks are the "purest" tasks that rely almost solely on color perception without interference of linguistics, culture or memory. Sometimes, color blindness derived from brain damage (such as cerebral achromatopsia) can affect the other color tasks while leaving the comparative color tasks untouched.

Other examples of comparative color tasks include:

Connotative color tasks require the subject to infer implicit information from a color. In addition to color vision, connotative color tasks require either cultural or natural knowledge to interpret the color's meaning.