I have been having issues with loading a local image into the skybox. This is my code.
<html>
...
.....
<body>
<a-scene>
<a-assets>
<img id="sky" src="test.jpg">
</a-assets>
<a-sky color="#6EBAA7" src="#sky"></a-sky>
</a-scene>
</body>
...
</html>
file structure is
|webvr
|index.htm
|test.jpg
all I get is a lime green background without any trace of an image.
The skybox is the a-sky, it's a spherical. If you have a cubemap you could convert it. I think there are a lot of tools out there. Or try the cubemap community code. Someone made it already.
If you only want to load an image to the sky, just use <a-sky src="#sky"></a-sky>
without the color. I think color overrides the image.
Edit: Ok, the color gets multiplied by the image. So you should see the image in a green tint. Edit2: Ok, if you load the page locally without any server, you won't see any images, they won't get loaded, as cors headers are missing and your local pc is not a local server. Just use mongoose. https://www.cesanta.com/products/binary :)