The CTT was developed to meet the need for a test with the sensitivity and specificity of the standard Trail Making Test (TMT), but one that was as free as possible from the influences of language and cultural bias. The CTT retains the psychometric properties of the standard TMT, but it substitutes the use of colour for the use of English alphabet letters, making it more suitable in cross-cultural and other special needs contexts. Instructions may be presented either verbally or with visual cues. Respondents must be able to recognize Arabic numerals from 1 to 25 and to distinguish between the colours pink and yellow. Research has shown the CTT to be comparable to the original TMT. The validity of the CTT has been documented in a variety of clinical and neuropsychological populations.