How can i add the colour to the function surf ?

Hello

All my curves are blue

How can i change their colour ?

How can i add the colour to this example:

y1 = [28 28.5 29 35 50];

y2 = [1e2 1e3 1e4];

y3 = [0.30566 0.31675837 0.3280565163 0.4793385 0.98557455 3.04709 3.157375 3.269625 4.77027 9.7606137 29.5405784 30.576361 31.628 45.4737503 88.77938];

[Y1,Y2]= meshgrid (y1*1e-3 , y2) ; %(20:20:100,0:0.2:1);

figure (2)

surf(Y1,Y2,y3)

xlabel ('Length of layers (mm)')

ylabel('Load resistance (\Omega)')

zlabel('Power (\muW/g^2)')

[Stephen23]

Does figure 2 already exist when this code is run?