Make a 15-channel output colored light

//I want to make a 15-channel color light, use P0.0~P0.7 and P2.0~P2.6 ports for output; the preset number is 15 1s (decimal 32767).
//Set two buttons +1 (P3.3) and -1 (P3.4).
//You can subtract to decimal 32047. If you continue to press the -1 button after reaching 32047, you can return to 32767 and subtract again.
//The same is true for addition. After adding to 32767, press the +1 button to return to 32047 and add 1 again.
//Set another button (P2.7). When P2.7 is grounded, subtract the decimal number 1712 from the currently displayed number to display it.
//Looking for a single-chip color light program.

Best answer:
//===========================
#include
sbit K_1 = P3^3; //＋
sbit K_2 = P3^4; //－
sbit D_1 = P2^7; //Display mode selection
//----------------------------
void delay_ms(unsigned int n)
{
    unsigned char j;
    while(n--) for(j = 0; j < 230; j++); //230 is obtained from experimental test!
}

void main()
{
    unsigned int m;
    m = 32767;
    while(1) {
      if (D_1 == 1) {
        P2 = ~(m / 256); 
        P0 = ~(m % 256);
      }
      else {
        P2 = ~ ((m - 1712) / 256);       
        P0 = ~((m - 1712) % 256);
      }
      if (K_1 == 0) {
        delay_ms(10);
        if (K_1 == 0) {
          m++;
          if (m > 32767) m = 32047;
          while(K_1 == 0);
      } }
      if (K_2 == 0) {
        delay_ms(10);
        if (K_2 == 0) {
          m--;
          if (m < 32047) m = 32767;
          while(K_2 == 0);
    } } }
}
//============================= 
The PROTEUS simulation screen of this program is as follows: