I have the published V.S. test, and have used it only very occasionally, when asked to, as part of, or separately from an assessment for Access Arrangements. It is a quick to administer, ‘Intuitive’ test and very low cost, which uses a number of coloured overlays.
When asked, I would, normally suggest seeing an optometrist for a far more thorough colorimetry test, used for determining the most appropriate tinted lenses. This would be more expensive and thorough procedure, usually including an overlay test in addition to the more sophisticated assessment for tinted lenses.
Many opticians/opthalmists across the country now undertake these assessments.