handling array from post data on espwebserver
The ability for PHP to do this is special to PHP. The PHP program parses the field names as PHP arrays if they are named thus:

&lt;form ....&gt;
&lt;input name="[colorsarray][0]" value="#ff0000" /&gt;
&lt;input name="[colorsarray][1]" value="#2d67ea" /&gt;
&lt;input name="[colorsarray][2]" value="#000000" /&gt;
&lt;input name="[colorsarray][3]" value="#7cf325" /&gt;
[...]
&lt;/form&gt;


But since the ESP8266's core doesn't use PHP or understand PHP arrays, you will have to use the literal field name [colorsarray][3], parse it yourself, and determine at run-time the length of the array and how much memory is needed, etc.