Question: So here is my issue:

I have a two-tone png image. One tone is black, one tone is transparent.

I am currently using the background color attribute to change the color of the transparent section dynamically. 

I would also like to be able to change the black section dynamically using a mask overlay. I assume this is possible in html5 canvas, and possibly css, but I have been unable to find a working answer.

Thank you for your help.

Answer: 
At this point, webkit (and only webkit) can do it with pure CSS. It's [really, really, really not supported](http://caniuse.com/#search=mask).

A couple links to get you started, should you be interested:

* <http://www.webkit.org/blog/181/css-masks/>
* <http://trentwalton.com/2011/05/19/mask-image-text/>
Well, canvas is supported by most modern browsers, if you can take jquery as a solution. You can try this jquery plugin.

the command is pretty straightforward and as easy as:

```
$("#myImageID").tancolor();

```

There's an interactive [demo](http://nicolaisi.github.io/tancolor/). You can play around with it.

Check out the documentation on the usage, it is pretty simple. [docs](https://github.com/nicolaisi/tancolor)