Map matrix into colors

Some context: I am working on a 2-dimensional 2 link hydraulic actuated robot arm. I am able to calculate the natural frequency(wn) using the two variables xp1 and xp2 (piston position 1 and piston position 2 - my two actuators) for all positions of the pistons. This yields a 100x100 matrix where i sweep the pistons from 0 to 0.35 (minimum to maximum length) and i am able to plot a contour plot using xp1 and xp2 as my x and y axis.

I would like to make a contour-like-plot in the reachable domain of the arm. The following code shows how i calculate the x and y values of my end effector point using only piston positions as variables.

Xp1 = linspace(0,0.35,100);
Xp2 = linspace(0,0.35,100);
[xp1,xp2] = meshgrid(Xp1,Xp2);

x=xe.*cos((w1-v1+acos((lOQ.^2+lOH.^2-(x1_min+xp1).^2)./(2.*lOQ.*lOH)))+(2.*pi-w2+v2-acos((lBW.^2+lBG.^2-(x2_min+xp2).^2)./(2.*lBW.*lBG))))-ye.*sin((w1-v1+acos((lOQ.^2+lOH.^2-(x1_min+xp1).^2)./(2.*lOQ.*lOH)))+(2.*pi-w2+v2-acos((lBW.^2+lBG.^2-(x2_min+xp2).^2)./(2.*lBW.*lBG))))+lOB.*cos((w1-v1+acos((lOQ.^2+lOH.^2-(x1_min+xp1).^2)./(2.*lOQ.*lOH))));
y=ye.*cos((w1-v1+acos((lOQ.^2+lOH.^2-(x1_min+xp1).^2)./(2.*lOQ.*lOH)))+(2.*pi-w2+v2-acos((lBW.^2+lBG.^2-(x2_min+xp2).^2)./(2.*lBW.*lBG))))+xe.*sin((w1-v1+acos((lOQ.^2+lOH.^2-(x1_min+xp1).^2)./(2.*lOQ.*lOH)))+(2.*pi-w2+v2-acos((lBW.^2+lBG.^2-(x2_min+xp2).^2)./(2.*lBW.*lBG))))+lOB.*sin((w1-v1+acos((lOQ.^2+lOH.^2-(x1_min+xp1).^2)./(2.*lOQ.*lOH))));

Now what i am kindly asking is how to 'map' my values of my natural frequency onto the domain of the end effector of the robot arm something along the lines of a contour plot. What i have been able to figure out so far is basically only the relationship of wn(xp1,xp2), x(xp1,xp2), y(xp1,xp2) and since they depend on the same variable, it should somehow be able to string these together. The start of the first arm is at origo. I have attached some pictures. Kind regards.

[Jonas Aarup]

Solved by making a 3D surf plot

surf(x,y,wn)

and rotating so the plot becomes a 2D plot.