Problem with contour function: the linecolor disappeared

Hi everyone, I met a problem with contour function.

%%f3 is a calculated martix
figure(1)
contour(kx_grid,ky_grid,f3,10,'linewidth',2);
k_contour = 2*pi.*(kx_grid.^2+ky_grid.^2).^(-0.5);
figure(2)
contour(kx_grid,ky_grid,f3,10,'linewidth',2);
hold 
k_contour = 2*pi.*(kx_grid.^2+ky_grid.^2).^(-0.5);
[C,h]=contour(kx_grid,ky_grid,k_contour,[50 100 200 400 800],':k','LineWidth',1,'LineStyle','--');
clabel(C,h,'color','r');
end

the results are

The linecolor of Figure 2 disappeared, can anyone tell me how to retain the color while plot the second contour. Thanks in advance!