How can I change the color of a subsystem during simulation based on the value of an input signal ?

Hello,

I would like to change the color of a subsystem if the input signal exceeds a constant value (or another signal). I found this function (found here : http://fr.mathworks.com/matlabcentral/answers/97099-how-can-i-change-the-color-of-a-subsystem-during-simulation-based-on-the-value-of-an-input-signal-in ) :

function y = fcn(u, t)

%#eml

eml.extrinsic('set_param','get_param','gcs');

y = u;

if u > t

       set_param(get_param(gcs,'parent'),'BackgroundColor','red');

else

       set_param(get_param(gcs,'parent'),'BackgroundColor','white');

end

But when I try it I get 3 error codes that I don't understand : 1) Unsupported n-D matrix access for n>2. Function 'Subsystem/Embedded MATLAB Function' (#76.131.175), line 7, column 1: "eml.extrinsic('set_param','get-param','gcs')"

2) Unsupported: structure access Function 'Subsystem/Embedded MATLAB Function' (#76.131.144), line 7, column 1: "eml.extrinsic".

3) Errors occured during parsing of Embedded MATLAB function 'Subsystem/Embedded MATLAB Function' (#76).

To simplify, I have a signal that can be 0 or 1, and I would like to have a subsystem block green if the signal is 0 and red if it is 1.

Could you help me please ? I use simulink 6.3 (2005).

Thank you