XYZ Layer in OpenLayers has missing tiles

Question

In OpenLayers I'm having a missing tile problem where it generates a missing link icon and a pink background. I found several threads including this one saying to add this code OpenLayers.Util.onImageLoadError = function() {this.src = '/img/blank.png';};

Sorry if this is dumb, but should my blank.png just be a 1px transparent png24? And also where should the img folder go?

Sorry, I've tried 1px, 256px, png24, png8, gif and putting the img folder and/or file in every conceivable place and I'm having no luck. Maybe you'll see something in these screenshots.

I've also tried an image with color to see if I can notice any actual change, so that's why the blank.png file looks red in the Finder thumbnail.

Answer 1

Woohoo! Figured it out. This thread had the solution to change the CSS rather than the JS.

.olImageLoadError { 
    /* when OL encounters a 404, don't display the pink image */
    display: none !important;
}

This help article was helpful too, but I have not idea how to tell TileMill/MapBox to generate blank tiles rather than missing tiles. I'll get there someday.