If you have a look at the extras.php file the colour arrays are all listed – you can change all of them at once that way, nice and easy!
You’ll find it here
* Output color scheme CSS in header
*/
function sugarspice_color_scheme() {
$color = array(
'green' => '#97C379',
'emerald' => '#36AB8A',
'mint' => '#9ED6BB',
'peach' => '#EECCCC',
'pink' => '#F8AFB8',
'red' => '#F03B42',
'violet' => '#BB86B4',
'babyblue' => '#A7DBD8',
'orange' => '#F66B40',
'yellow' => '#fff568',
);
and you can even see that I’ve changed the colour for the “peach” setting on mine to EECCCC – that should give you an idea of what you need to change.