====Colour data====
Colours are special data values which can be provided to certain styling macros, such as [[harlowe:background|(background:)]]
or [[harlowe:text-colour|(text-colour:)]]. You can use built=in named colour values, or create other colours using the
[[harlowe:rgb|(rgb:)]] or [[harlowe:hsl|(hsl:)]] macros.

The built-in values consist of the following:

^Value ^ HTML equivalent ^
| ''red'' | ''#e61919''|
| ''orange'' | ''#e68019''|
| ''yellow'' | ''#e5e619''|
| ''lime'' | ''#80e619''|
| ''green'' | ''#19e619''|
| ''aqua'' or ''cyan'' | ''#19e5e6''|
| ''blue'' | ''#197fe6''|
| ''navy'' | ''#1919e6''|
| ''purple'' | ''#7f19e6''|
| ''magenta'' or ''fuchsia'' | ''#e619e5''|
| ''white'' | ''#fff''|
| ''black'' | ''#000''|
| ''grey'' or ''gray'' | ''#888''|

(These colours were chosen to be visually pleasing when used as both background colours and text colours, without
the glaring intensity that certain HTML colours, like pure #f00 red, are known to exhibit.)

In addition to these values, and the [[harlowe:rgb|(rgb:)]] macro, you can also use HTML hex #xxxxxx and #xxx notation to specify
colours, such as ''%%#691212%%'' or ''%%#a4e%%''. (Note that these are //not// [[harlowe:string|strings]], but bare values - ''%%(background: #a4e)%%''
is valid, as is ''%%(background:navy)%%''.) Of course, HTML hex notation is notoriously hard to read and write, so this
isn't recommended.

If you want to quickly obtain a colour which is the blending of two others, you can blend them
using the ''%%+%%'' operator: ''%%red + orange + white%%'' produces a blend of red and orange, tinted
white. ''%%#a4e + black%%'' is a dim purple.

Like [[harlowe:datamap|datamaps]], colour values have a few read-only data names, which let you examine the **r**ed, **g**reen and **b**lue
components that make up the colour, as well as its **h**ue, **s**aturation and **l**ightness.

^Data name^
| ''r'' | ''$colour's r'' | The red component, a whole number from 0 to 255.|
| ''g'' | ''$colour's g'' | The green component, a whole number from 0 to 255.|
| ''b'' | ''$colour's b'' | The blue component, a whole number from 0 to 255.|
| ''h'' | ''$colour's h'' | The hue angle in degrees, a whole number from 0 to 359.|
| ''s'' | ''$colour's s'' | The saturation percentage, a fractional number from 0 to 1.|
| ''l'' | ''$colour's l'' | The lightness percentage, a fractional number from 0 to 1.|

These values can be used in the [[harlowe:hsl|(hsl:)]] and [[harlowe:rgb|(rgb:)]] macros to produce further colours. Note that some of these values
do not transfer one-to-one between representations! For instance, the hue of a gray is essentially irrelevant, so grays
will usually have a ''%%h%%'' value equal to 0, even if you provided a different hue to [[harlowe:hsl|(hsl:)]]. Furthermore, colours with a
lightness of 1 are always white, so their saturation and hue are irrelevant.