I'm currently fetching the color as a a HEX via a GET request to a service, which is returning a String value such as "#ff0000"

I need to convert the string value from the GET request into a uint_16 so that I can set the color.

uint16_t color = (uint16_t) strtol(http.getString(), NULL, 16);

Which gives me the error

cannot convert 'String' to 'const char*' for argument '1' to 'long int strtol(const char*, char**, int)'

Any recommended way to generate the uint_16 color from a HEX string?