ATtiny85 LED Flicker

#define F_CPU 8000000UL
#define LED_DELAY 1 //Overall effect delay
#include <avr/io.h>
#include <util/delay.h>
#include <avr/interrupt.h>

int brightness1 = 0;
int brightness2 = 64;
int led_delay1 = 0;
int led_delay2 = 0;
char led_direction = 1;

int main(void) {
//Initialise code here

//Set Timer0 prescaler
  DDRB = 0x13; //PB0 = 1, PB1 = 2, PB2 = 4, PB3 = 8, PB4 = 10
  TCCR0A = (1 << COM0B1)|(1 << COM0A1)|(1 << WGM00); //PWM mode
  TCCR0B = (1 << CS01)|(1 << CS00); //div64
  OCR0A = 0; //PB0
  OCR0B = 0; //PB1
  
//Set Timer1 prescaler
  GTCCR = (1 << PWM1B)|(1 << COM1B0); //PWM mode
  TCCR1 = (1 << CS12)|(1 << CS11)|(1 << CS10); //div64
  OCR1B = 0; //PB4
 
//Main loop
	while (1) {
	    
		//led_delay parameter allow tweaking of each LED output
	    if(led_delay2==5){
	    	OCR0A = brightness1 + 89;
		    led_delay2 = 0;
	    }
	    
		//Scroll the red LED up and down across 150ms * (254 - 64) seconds
	    if(led_delay1==150){
            OCR0B = brightness2;
			
			if(led_direction){
				brightness2++;
			} else {
				brightness2--;
			}
			
			//Keep the red LED brightness between 64 and 254 (dim and bright, but not off)
		    if((brightness2<=64)||(brightness2>=254)){
				led_direction = !led_direction;
			}
			
            led_delay1 = 0;
	    }
	    
		brightness1 = brightness1 + 13;
		OCR1B = brightness1;
		
		_delay_ms(LED_DELAY);
		led_delay1++;
		led_delay2++;
	}

	return 1;
}