Hi,
It's the file "administrator/components/com_hikashop/classes/filter.php"
You will find the hard-coded color in the function "cursorTitlePosition" of the class hikashopCursorClass.
We will see to extract this value from the class in order to let it available in the filter configuration... Or use a generic class.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.