Coloring a surf() plot by value

Hey all,

I've made a surf plot of training times for an SVM, depending on values of C and gamma (so C and gamma as x and y, and training time as f(x,y)). All training times less than 1 second are acceptable, and I would like to show that in the plot. So the question is; How can I make the surf() plot a different color for values above 1 (second), when I don't have a fixed minimum/maximum value?