
function y=ry(dark)

nc=64;nc2=nc/2;
%dark=.5;

% the red bit

y=colormap;

% yellow to grey [1 1 0] -> [dark dark dark ]

y(1:nc2,1)=1-(1-dark)/nc2*(1:nc2)';
y(1:nc2,2)=1-(1-dark)/nc2*(1:nc2)';
y(1:nc2,3)=dark/nc2*(1:nc2)';

% grey to red [dark dark dark]-> [1 0 0]

y(nc2+1:nc,1)=dark+(1-dark)/nc2*(1:nc2)';
y(nc2+1:nc,2)=dark-dark/nc2*(1:nc2)';
y(nc2+1:nc,3)=dark-dark/nc2*(1:nc2)';



 