The Oasys JS API uses RGB colour definitions, where all colour is defined using Red Green Blue values that vary between 0 and 255. This allows for over 16 million colours but the RGB definition makes it difficult to vary colour in a natural way.

One alternative way to define colour is HSV: hue/saturation/value (also known as HSB: hue/saturation/brightness). With this definition it is possible to vary colours in more natural ways by increasing/decreasing one of the 3 values.

The functions included with this script are:

RGB2HSV(R,G,B)
– Inputs are R,G,B values which should be integer and be between 0 and 255.
– Output is an object with properties .h .s .v, corresponding to the equivalent HSV colour.

HSV2RGB(R,G,B)
– Inputs are H,S,V values which should be numeric and 0-360 for H, and 0-100 for S and V.
– Output is an object with properties .r .g .b, corresponding to the equivalent RGB colour (as integers between 0-255).

The script allows users to work with HSV colours before swapping to RGB for use with Colour.RGB( ) in the Oasys API.

The script comes with a _example file that shows how it works with a little GUI in PRIMER, D3PLOT or T-HIS.