Ended up going with something like this:

Ended up going with something like this:

#include <RFduinoBLE.h>

// State properties.
int state = 1;
char command;
String hexstring;

// RGB pins.
int redPin = 2;
int grnPin = 3;
int bluPin = 4;

// Setup function to set RGB pins to OUTPUT pins.
void setup () {
  pinMode(redPin, OUTPUT);
  pinMode(grnPin, OUTPUT);
  pinMode(bluPin, OUTPUT);

  // This is the data we want to appear in the advertisement
  // (the deviceName length plus the advertisement length must be <= 18 bytes.
  RFduinoBLE.deviceName = "iOS";
  RFduinoBLE.advertisementInterval = MILLISECONDS(300);
  RFduinoBLE.txPowerLevel = -20;
  RFduinoBLE.advertisementData = "rgb";

  // Start the BLE stack.
  RFduinoBLE.begin();
}

void loop () {
  switch (command) {
    case 1:
      // Blink.
    break;
    case 2:
      // Fade.
    break;
  }

  //RFduino_ULPDelay(INFINITE);
}

// Converts HEX as a String to actual HEX values.
// This is needed to properly convert the ASCII value to the hex
// value of each character.
byte getVal (char c) {
  if (c >= '0' && c <= '9') return (byte)(c - '0');
  else return (byte)(c - 'a' + 10);
}

// Process each function/command.
void processCommand (int command, String hex) {
  switch (command) {
    case 'b':
      command = 1; // Set blink mode.
    break;
    case 'f':
      command = 2; // Set fade mode.
    break;
    case 'c':
      // We put together 2 characters as is
      // done with HEX notation and set the color.
      byte red = getVal(hex.charAt(1)) + (getVal(hex.charAt(0)) << 4);
      byte green = getVal(hex.charAt(3)) + (getVal(hex.charAt(2)) << 4);
      byte blue = getVal(hex.charAt(5)) + (getVal(hex.charAt(4)) << 4);

      // Set the color.
      setColor (red, green, blue);
    break;
  }
}

// Sets the color of each RGB pin.
void setColor (byte red, byte green, byte blue) {
  analogWrite(redPin, red);
  analogWrite(grnPin, green);
  analogWrite(bluPin, blue);
}

// This function returns data from the radio.
void RFduinoBLE_onReceive (char *data, int len) {
  for (int i = 0; i < len; i++) {
    stateMachine(data[i]);
  }
}

// Main state machine function, which processes
// data depending on the bytes received.
void stateMachine (char data) {
  switch (state) {
    case 1:
      if (data == 1) {
        state = 2;
      }
    break;
    case 2:
      if (data == 'b' || data == 'f' || data == 'c') {
        command = data;
        hexstring = "";
        state = 3;
      } else if (data != 1) { // Stay in state 2 if we received another 0x01.
        state = 1;
      }
    break;
    case 3:
      if ((data >= 'a' && data <= 'z') || (data >= '0' && data <= '9')) {
        hexstring = hexstring + data;
        if (hexstring.length() == 6) {
          state = 4;
        }
      } else if (data == 1) {
        state = 2;
      } else {
        state = 1;
      }
    break;
    case 4:
      if (data == 3) {
        processCommand(command, hexstring);
        state = 1;
      } else if (data == 1) {
        state = 2;
      } else {
        state = 1;
      }
    break;
  }
}

#include <RFduinoBLE.h>

// State properties.
int state = 1;
char command;
String hexstring;

// RGB pins.
int redPin = 2;
int grnPin = 3;
int bluPin = 4;

// Setup function to set RGB pins to OUTPUT pins.
void setup () {
  pinMode(redPin, OUTPUT);
  pinMode(grnPin, OUTPUT);
  pinMode(bluPin, OUTPUT);

  // This is the data we want to appear in the advertisement
  // (the deviceName length plus the advertisement length must be <= 18 bytes.
  RFduinoBLE.deviceName = "iOS";
  RFduinoBLE.advertisementInterval = MILLISECONDS(300);
  RFduinoBLE.txPowerLevel = -20;
  RFduinoBLE.advertisementData = "rgb";

  // Start the BLE stack.
  RFduinoBLE.begin();
}

void loop () {
  switch (command) {
    case 1:
      // Blink.
    break;
    case 2:
      // Fade.
    break;
  }

  //RFduino_ULPDelay(INFINITE);
}

// Converts HEX as a String to actual HEX values.
// This is needed to properly convert the ASCII value to the hex
// value of each character.
byte getVal (char c) {
  if (c >= '0' && c <= '9') return (byte)(c - '0');
  else return (byte)(c - 'a' + 10);
}

// Process each function/command.
void processCommand (int command, String hex) {
  switch (command) {
    case 'b':
      command = 1; // Set blink mode.
    break;
    case 'f':
      command = 2; // Set fade mode.
    break;
    case 'c':
      // We put together 2 characters as is
      // done with HEX notation and set the color.
      byte red = getVal(hex.charAt(1)) + (getVal(hex.charAt(0)) << 4);
      byte green = getVal(hex.charAt(3)) + (getVal(hex.charAt(2)) << 4);
      byte blue = getVal(hex.charAt(5)) + (getVal(hex.charAt(4)) << 4);

      // Set the color.
      setColor (red, green, blue);
    break;
  }
}

// Sets the color of each RGB pin.
void setColor (byte red, byte green, byte blue) {
  analogWrite(redPin, red);
  analogWrite(grnPin, green);
  analogWrite(bluPin, blue);
  delay(200);
}

// This function returns data from the radio.
void RFduinoBLE_onReceive (char *data, int len) {
  for (int i = 0; i < len; i++) {
    stateMachine(data[i]);
  }
}

// Main state machine function, which processes
// data depending on the bytes received.
void stateMachine (char data) {
  switch (state) {
    case 1:
      if (data == 1) {
        state = 2;
      }
    break;
    case 2:
      if (data == 'b' || data == 'f' || data == 'c') {
        command = data;
        hexstring = "";
        state = 3;
      } else if (data != 1) { // Stay in state 2 if we received another 0x01.
        state = 1;
      }
    break;
    case 3:
      if ((data >= 'a' && data <= 'z') || (data >= '0' && data <= '9')) {
        hexstring = hexstring + data;
        if (hexstring.length() == 6) {
          state = 4;
        }
      } else if (data == 1) {
        state = 2;
      } else {
        state = 1;
      }
    break;
    case 4:
      if (data == 3) {
        processCommand(command, hexstring);
        state = 1;
      } else if (data == 1) {
        state = 2;
      } else {
        state = 1;
      }
    break;
  }
}