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 that are named according to ECDIS display modes. The files are located, by default, in C:\ProgramFiles\CARIS\Caris\<version>\system\S57Config
\symbolization\colcalib.
The same colour token can be represented by different colour values across different ECDIS 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) is also available. 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 token. 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> |