Colour tables define what colours are used by S-52 and S-101 portrayals. Colours are represented by five-character colour tokens. These tokens are stored in files based on ECDIS display modes. The files are located, by default, in .C:\Program Files\CARIS\<Product>\<version>\system\S57Config
\symbolization\colcalib.
RGB (red, blue, green) values are set according the ECDIS display mode. This means that the same colour token can be represented by different values across different display modes. For example, CHMGD colour token is represented in day_bright.xml as
<Colour Index="9" Type="RGB" Token="CHMGD"> |
<R>232</R> |
<G>69</G> |
<B>196</B> |
</Colour> |
However, in night_bright.xml, CHMGD is represented as
<Colour Index="9" Type="RGB" Token="CHMGD"> |
<R>88</R> |
<G>30</G> |
<B>73</B> |
</Colour> |
CMYK (cyan, magenta, yellow and key) and HSL (hue, saturation, lightness) can be also be used. For example, the CHMGD token in day_bright.xml can be represented as below.
<Colour Index="9" Type="CMYK" Token="CHMGD"> |
<C>0</C> |
<M>70</M> |
<Y>15</Y> |
<K>9</K> |
</Colour> |
The same colour token in HLS is shown below.
<Colour Index="9" Type="HLS" Token="CHMGD"> |
<H>313</H> |
<L>59</L> |
<S>78</S> |
</Colour> |
Transparencies can be created using the Alpha tag.
The alpha value sets the visibility of a colour layer. A value of 0 means that the colour is completely transparent, and its features are invisible. A value of 100 means that the colour is completely opaque; areas beneath any feature on the layer are not visible.
In the following example, the colour is set to 80% transparency.
<Colour Index="9" Type="CMYK" Token="CHMGD"> |
<C>0</C> |
<M>30</M> |
<Y>0</Y> |
<K>0</K> |
<A>20</A> |