Surface plot contour values

I am trying to set the backgound vorticity levels of my contour plot to be the same color so that only values above this are shown. I would like the values between -10 and 10 to be the same color so that no contours are shown between these values. This is the loop I have so far. I would like this change to be reflected to each frame as well. I have attached an image of one of the frames to show what I am generating currently.

for z=1:1:25
    f=figure('visible','off');
    Vorticity(:,:,z)=dvdx(:,:,z)-dudy(:,:,z);
    contourf(X,Y,Vorticity(:,:,z));
    caxis([-25 25]);
    ivcb2=colorbar; 
    ivcb2.Label.String = '1/s'; 
    w32 = ivcb2.FontSize;
    ivcb2.FontSize = 12;
    xlabel('X (m)');
    ylabel('Y (m)');
    title('StaticMakoVorticity2');
    Mvort2(z)=getframe(gcf);
end