contour with gray colormap using external tools

Besides the solution presented above it is possible to use the tools freezeColors and COLORMAP and COLORBAR utilities to change the colormap in a single figure.

% use these libraries
addpath('ColorbarUtilities');
addpath('freezeColors');
 
hold on;
caxis([0 1]);
colormap(jet(colorDepth));
hplot = pcolor(x,y,data); shading flat        
 
% colorbar
hcb = colorbar('location','EastOutside', ...
    'FontSize'   , FontSize    , ...
    'FontName'   , FontName    , ...
    'Ylim'       , [0 1]       , ...
    'Box'        , 'on'        , ...
    'TickDir'    , 'in'        , ...
    'TickLength' , [.02 .02]   , ...
    'LineWidth'  , 0.6);
 
% freeze colorbar
cbfreeze;  
% apply label to colorbar 
% - here with cblabel 
hcLabel = cblabel(zLabelText);
set([hcLabel], ...
    'FontSize'   , FontSize    , ...
    'FontName'   , FontName);
 
% freeze colors (allows multiple colormaps)
freezeColors;  
 
% plot contour with different colormap
colormap(gray(colorDepth));
[C,hfigc] = contour(x, y, data,[0:0.1:1]);
set(hfigc, 'LineWidth',1.0);
 
hold off;