If subtle means "completely the wrong thing" - if it were the "Ruby Editors Software Tree" or something, it'd be OK :) A nicely drawn pause symbol would be soooo much prettier & nicer & simpler & neater & more meaningful and even more subtle, as evidenced by the fact that most people don't know what it is<g>
I'm almost tempted to drag out the GIMP and do one myself (being English, I almost said 'knock one out', but I'm aware of the connotations thank you...)