Colour Selections Calculator

Colour Selections Calculator

This calculator works best on desktop computers. For mobile devices use landscape mode. Please allow for tolerances as LRV numbers are calculated as whole numbers whereas the Contrast is in percentage format.

Input any 2 fields below
LRV 1:
LRV 2:
Contrast: %
Contrast: %

LRV stands for Luminance Reflectance Value
TGSI stands for Tactile Ground Surface Indicator

The contrast formula used in the app for Australia is the Bowman-Sapolinski Equation with LRV readings which are to be obtained as noted in Part E3 or E5 of AS/NZ 1428.4.1-2009 and Part B4 of AS1428.1-2009 is

125(Y2-Y1) / (Y1+Y2+25)
where Y2 is the LRV of the lighter area and Y1 is the LRV of the darker area.

Directions for use of calculator:
Input any two fields and the results will provide the response to the missing third field. In some cases the response
can result in 2 LRV readings. This is because a colour can achieve the same luminance contrast with use of a much
darker colour or a much lighter colour.
Where luminance contrast is a minimum of 30%, it is suitable for use for building elements such as doorways, stair nosings,
toilet seats and integrated TGSIs (Tactile Ground Surface Indicators).
Where luminance contrast is a minimum of 45%, it is suitable for use for Discrete TGSIs
Where luminance contrast is a minimum of 60%, it is suitable for use for Composite TGSIs

Please refer to AS/NZ1428 suite of Australian Standards for details.

Note that LRV is on a scale of 0 to 100 (black to white), however both white and black are never absolute and therefore in reality B1/Y2 never equals 100 and B2/Y1 is always greater than 0.

Use app at your own risk. The app designer / Vista Access Architects shall not be held liable for use of the app.