Relationship between Arduino mega board Timers and Interrupt pins

What is the relationship between Arduino mega board Timers and Interrupt pins. I want to use two TCS230 color sensors in my project.

I found the following code example for one color sensor.

int s0=3,s1=4,s2=5,s3=6;
int flag=0;
int counter=0;
int countR=0,countG=0,countB=0;
void setup()
{
Serial.begin(115200);
pinMode(s0,OUTPUT);
pinMode(s1,OUTPUT); 
pinMode(s2,OUTPUT);
pinMode(s3,OUTPUT);
}
void TCS()
{
  digitalWrite(s1,HIGH);
  digitalWrite(s0,LOW);
  flag=0;
  attachInterrupt(0, ISR_INTO, CHANGE);
  timer2_init();
}
void ISR_INTO()
{
  counter++;
}
void timer2_init(void)
{
  TCCR2A=0x00;
  TCCR2B=0x07; //the clock frequency source 1024 points
  TCNT2= 100;    //10 ms overflow again
  TIMSK2 = 0x01; //allow interrupt
}
int i=0;
ISR(TIMER2_OVF_vect)//the timer 2, 10ms interrupt overflow again. Internal overflow interrupt executive function
{
TCNT2=100;
flag++;
if(flag==1)
 {
   counter=0;
 }
else if(flag==2)
  {
   digitalWrite(s2,LOW);
   digitalWrite(s3,LOW); 
   countR=counter/1.051;
   Serial.print("red=");
   Serial.println(countR,DEC);
   digitalWrite(s2,HIGH);
   digitalWrite(s3,HIGH);   
  }
else if(flag==3)
   {
    countG=counter/1.0157;
   Serial.print("green=");
   Serial.println(countG,DEC);
    digitalWrite(s2,LOW);
    digitalWrite(s3,HIGH); 
    }
else if(flag==4)
   {
    countB=counter/1.114;
   Serial.print("blue=");
   Serial.println(countB,DEC);
    digitalWrite(s2,LOW);
    digitalWrite(s3,LOW);
    }
else
    {
    flag=0; 
     TIMSK2 = 0x00;
    }
    counter=0;
    delay(2);
}
void loop()
{
 delay(10);
 TCS();
 if((countR>10)||(countG>10)||(countB>10))
  {
     if((countR>countG)&&(countR>countB))
      {
           Serial.print("red");
           Serial.print("\n");
           delay(1000);
      }
     else if((countG>=countR)&&(countG>countB))
      {
           Serial.print("green");
           Serial.print("\n");
           delay(1000);
      } 
    else if((countB>countG)&&(countB>countR))
     {
           Serial.print("blue");
           Serial.print("\n");
          delay(1000);
     }
   }
 else 
 {
    delay(1000);       
 }
}

How do i use another color sensor in a similar way, or is there any other technique available for using two TCS230 sensors

Did you look at Paragraph 14 of the Mega2560 datasheet? There are 57 interrupt sources, many coming from Timers and Interrupt pins. (and which do not Copy & Paste well here:

Vector No., Program Address, Source, Interrupt Definition
1, $0000, RESET, External Pin, Power-on Reset, Brown-out Reset, Watchdog Reset, and JTAG AVR Reset
2, $0002, INT0, External Interrupt Request 0
3 $0004 INT1 External Interrupt Request 1
4 $0006 INT2 External Interrupt Request 2
5 $0008 INT3 External Interrupt Request 3
6 $000A INT4 External Interrupt Request 4
7 $000C INT5 External Interrupt Request 5
8 $000E INT6 External Interrupt Request 6
9 $0010 INT7 External Interrupt Request 7
10 $0012 PCINT0 Pin Change Interrupt Request 0
11 $0014 PCINT1 Pin Change Interrupt Request 1
12 $0016 PCINT2 Pin Change Interrupt Request 2
13 $0018 WDT Watchdog Time-out Interrupt
14 $001A TIMER2 COMPA Timer/Counter2 Compare Match A
15 $001C TIMER2 COMPB Timer/Counter2 Compare Match B
16 $001E TIMER2 OVF Timer/Counter2 Overflow
17 $0020 TIMER1 CAPT Timer/Counter1 Capture Event
18 $0022 TIMER1 COMPA Timer/Counter1 Compare Match A
19 $0024 TIMER1 COMPB Timer/Counter1 Compare Match B
20 $0026 TIMER1 COMPC Timer/Counter1 Compare Match C
21 $0028 TIMER1 OVF Timer/Counter1 Overflow
22 $002A TIMER0 COMPA Timer/Counter0 Compare Match A
23 $002C TIMER0 COMPB Timer/Counter0 Compare match B
24 $002E TIMER0 OVF Timer/Counter0 Overflow
25 $0030 SPI, STC SPI Serial Transfer Complete
26 $0032 USART0 RX USART0 Rx Complete
27 $0034 USART0 UDRE USART0 Data Register Empty
28 $0036 USART0 TX USART0 Tx Complete
29 $0038 ANALOG COMP Analog Comparator
30 $003A ADC ADC Conversion Complete
31 $003C EE READY EEPROM Ready
32 $003E TIMER3 CAPT Timer/Counter3 Capture Event
33 $0040 TIMER3 COMPA Timer/Counter3 Compare Match A
34 $0042 TIMER3 COMPB Timer/Counter3 Compare Match B
35 $0044 TIMER3 COMPC Timer/Counter3 Compare Match C
36 $0046 TIMER3 OVF Timer/Counter3 Overflow
37 $0048 USART1 RX USART1 Rx Complete
38 $004A USART1 UDRE USART1 Data Register Empty
39 $004C USART1 TX USART1 Tx Complete
40 $004E TWI 2-wire Serial Interface
41 $0050 SPM READY Store Program Memory Ready
42 $0052 TIMER4 CAPT Timer/Counter4 Capture Event
43 $0054 TIMER4 COMPA Timer/Counter4 Compare Match A
44 $0056 TIMER4 COMPB Timer/Counter4 Compare Match B
45 $0058 TIMER4 COMPC Timer/Counter4 Compare Match C
46 $005A TIMER4 OVF Timer/Counter4 Overflow
47 $005C TIMER5 CAPT Timer/Counter5 Capture Event
48 $005E TIMER5 COMPA Timer/Counter5 Compare Match A
49 $0060 TIMER5 COMPB Timer/Counter5 Compare Match B
50 $0062 TIMER5 COMPC Timer/Counter5 Compare Match C
51 $0064 TIMER5 OVF Timer/Counter5 Overflow
52 $0066 USART2 RX USART2 Rx Complete
53 $0068 USART2 UDRE USART2 Data Register Empty
54 $006A USART2 TX USART2 Tx Complete
55 $006C USART3 RX USART3 Rx Complete
56 $006E USART3 UDRE USART3 Data Register Empty
57 $0070 USART3 TX USART3 Tx Complete

In that code there is no relationship between the hardware interrupt on the pin and the timer interrupt. They are doing two different things. You could use whichever timer you want as long as you set it up right. You could change the pin interrupt to any other pin that supports hardware interrupts and it would work the same.