Returning the index of a stringarray value

Question

im trying to return the index of a string in my array upon I get it as input, I seem to get 9 for every color I input can you help me fix this?

ps "this may seem obvious but Im not very experienced"

  int FindIndex( const char a[][10], int size, char value[10] )
{
    int index = 0;

    while ( index < size && a[index] != value ) ++index;

    printf("%d", index);
    return ( index == size ? -1 : index );   
}

int main()
{
  char str[10];
  char colors[][10] = {
                      "BLACK","BROWN",
                      "RED","ORANGE",
                      "YELLOW","GREEN",
                      "BLUE","VIOLET",
                      "GREY","WHITE"
                      };

  printf("what resistor?\n");
  scanf("%s",str);

  FindIndex(colors,9,str);

}

Answer 1

int FindIndex( const char a[][10], int size, char value[10] )
{
  int found = -1;

  for(int i = 0; i < size; ++i) {
    if(strcmp(a[i], value) == 0) {
      found = i;
      break;
    }
  }

  printf("%d", found);

  return found;
}

Or as suggested by @Aconcagua, in a more concise form:

int FindIndex( const char a[][10], int size, char value[10] )
{

  for(int i = 0; i < size; ++i) {
    if(strcmp(a[i], value) == 0) {
       printf("%d", i);
       return i;
     }
  }

  return -1;
}