How to parse string like "FF33BB" to 3 bytes ? ..for LEDStripe

Hi,

in my code i want so set the color for a rgb led stripe. I use the WS2811Driver library.

I tried this but it doesn't work:

// blink_strip - ws2811 led strip blink example
// 11-15-2012 Initial Version 0.1

#include <WS2811Driver.h>
byte leds0[30];
byte leds1[30];


// 24 bits of color data stored GGRRBB
//const uint8_t leds0[] = { 0x00,0xff,0x00, 0xff,0x00,0x00, 0x00,0x00,0xff, 0xff,0xff,0xff }; // R,G,B,W
//const uint8_t leds1[] = { 0x00,0x00,0x00, 0x00,0x00,0x00, 0x00,0x00,0x00, 0x00,0x00,0x00 }; // 0,0,0,0,

WS2811Driver ledStrip; // uses P1_7 as datapin connect to DIN on strip

void setup(void)
{
    ledStrip.setLEDCount(10); // setup for 4 leds on a strip
    ledStrip.begin();        // configure P1.7 for output
}

void loop() {
    //ledStrip.write(leds0);               // set leds to red,green,blue,white
    //delay(500);
    //ledStrip.write(leds1,sizeof(leds1)); // turn off all 4 leds
    //delay(500);
    String color = "0000FF";
    
    for(byte x = 0; x < 30 ; x++){
      leds0[x] = byte('F');
      //leds0[x+1] = byte(color.substring(2,3));
      //leds0[x+2] = byte(color.substring(4,5));
      }  
    ledStrip.write(leds0); 
    delay(5000);
    for(byte x = 0; x < 30 ; x++){
      leds1[x] = 0x00;
      //leds0[x+1] = byte(color.substring(2,3));
      //leds0[x+2] = byte(color.substring(4,5));
      }  
     ledStrip.write(leds1); 
     delay(5000);
}

How can I convert the string to 3 bytes?