
<p>
Clicking either of the two buttons on the left of this section change how colour is used in the map.
</p>

<p>
When <b>Constraints</b> is selected, the colours in the map show information about the <i>problem</i>:
</p>

<ul class="org-ul">
<li>Blue elements are optional for inclusion in the network, if they improve the solution</li>
<li>Red elements are required to be included in the network, whether or not this improves the solution</li>
<li>Supply sites are coloured in orange</li>
<li>Everything else