Installation
npm install --save favicon-uri
Command line usage
Pass any valid css hex color or named color and favicolor will write the corresponding data uri to stdout.
I like using these for favicons, but you can use them however you like.
$ favicolor steelblue
data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAklEQVR4AewaftIAAAALSURBVGNwa9ryHwAFCgJ8ShCPgQAAAABJRU5ErkJggg==
You can then use that in an image tag
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAklEQVR4AewaftIAAAALSURBVGNwa9ryHwAFCgJ8ShCPgQAAAABJRU5ErkJggg==" width="15" height="15">
Or a favicon tag:
<link rel="icon" type="image/png" href="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAklEQVR4AewaftIAAAALSURBVGNwa9ryHwAFCgJ8ShCPgQAAAABJRU5ErkJggg==">
Examples
favicolor steelblue → 
favicolor "#bada55" → 
favicolor rebeccapurple → 