Specify which SCALE to use to decide the colour of the icon for this node.

After the percentage usage is calculated (using BANDWIDTH/MAXVALUE and data from the TARGET line), the colour is decided by looking up the percentage against this SCALE. If there is no USEICONSCALE line, then no scale is used, and the icon colour does not change.

Hint: This facility works best when you start with greyscale images.

NOTE: Prior to 0.97, Icon colourising used the PHP imagefilter() function. This function is only available in the version of GD that is bundled with PHP, and not with the official GD library. Several popular operating systems (e.g. Debian/Ubuntu) use the official GD library rather than the bundled PHP library. If you know that you do have the imagefilter function, and you prefer the 'old-style' coloring, then you can add SET use_imagefilter 1 in the top section of your map config file, to use imagefilter instead.