Holder is a lightweight (4kb) JavaScript image placeholder library that uses canvas to display the placeholders.
Themes can be used to style the placeholders which consist of a background colour, foreground colour and minimum font size.
To use a specific theme, the placeholder is displaying using:
<img data-src="holder.js/100x200/theme">
Although, an image can be customised individually using:
<img data-src="holder.js/100x200/#000:#fff">