nbsp;:&nbsp;<span class="keywordsign">'</span>a&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;string;<br>
&nbsp;&nbsp;&nbsp;&nbsp;usage&nbsp;:&nbsp;string;<br>
&nbsp;&nbsp;&nbsp;&nbsp;env_var&nbsp;:&nbsp;string;<br>
&nbsp;&nbsp;}<br>
&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;color&nbsp;:&nbsp;<span class="constructor">Misc</span>.<span class="constructor">Color</span>.setting&nbsp;option&nbsp;<span class="constructor">Stdlib</span>.ref<br>
&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;color_r