html5 canvas game on mobilesafari darkening on tap

i am developing a html5-canvas game which runs fine on most browsers, even mobile.

though on safari mobile if you tap on the canvas, it gets slightly darker - like if you tap on any html el开发者_如何学Cement. i guess this is for selection purposes.

is there any way to disable this darkening?

I think what you're seeing is indeed the selection of the canvas object. You could try hiding the highlight colour by setting the alpha to 0.

* {-webkit-tap-highlight-color: rgba(0,0,0,0);}

There is a CSS rule you can use: -webkit-user-select: none;.