Matrix in C++ With Multi color

#include<iostream>
#include<conio.h>
#include<windows.h>
using namespace std;
int main()
{
int i;
int b;
char a[100]={'1','0','1','0','1','0','4','1','0','1','0','g','g','e','r','t','a','x','c','g','y','u','g','v','g','d',};
while(1)
{
        system("Title The Matrix");
        system("color 0a");
        Sleep(100);
         
for(i=0;i<30;i++)
{
    
                         
       b = rand()%90;
      
         cout <<a[b];
         if(a[b]=='g')
         system("color 0b");
          if(a[b]=='g')
         system("color 0c");
          if(a[b]=='g')
         system("color 0d");
          cout <<"  ";    
  }
  cout <<"\n";
 
}
  getch();
  return 0;
 
}