version
x=linspace(0,2*pi,n=64);
Y=[sin(x);cos(x);tan(x);cot(x)]';
figure(); clf; cla;
CO=gray(4);
set(gca,'colororder',CO);
plot(x,Y,";;");
ylim([-1,1]);
current_CO=get(gca,"colororder");
if (size(current_CO)==size(CO))
  if (current_CO==CO)
    printf("colororder worked.\n");
  else
    warning("wrong colororder.\n");
  endif
else
  warning("set colororder did not work");
endif

