直接上：

#include<bits/stdc++.h>

#include<windows.h>
const char a[16]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};           
using namespace std;
void x(int i){
	if(i=='0')system("color 01");
	if(i=='1')system("color 10");
	if(i=='2')system("color 20");
	if(i=='3')system("color 30");
	if(i=='4')system("color 40");
	if(i=='5')system("color 50");
	if(i=='6')system("color 60");
	if(i=='7')system("color 70");
	if(i=='8')system("color 80");
	if(i=='9')system("color 90");
	if(i=='A')system("color A0");
	if(i=='B')system("color B0");
	if(i=='C')system("color C0");
	if(i=='D')system("color D0");
	if(i=='E')system("color E0");
	if(i=='F')system("color F0");
	
	
}
int main(){
    while(1){
    	for(int i=0;i<16;i++){
    	    
			system("cls");
    		x(a[i]);
    	    Sleep(1000);
	    
	}
	}
    
	return 0;
}