Transparent PNG background appears white

[Anthoang]

The transparent png files for the LCD Clock Example appears correctly in the Ionic watch as transparent.  

However, any other transparent png file imported into the project has a white background.  Are there any documentation on how a transparent png file is supposed to be created?  

[JonFitbit · Accepted solution]

The LCD clock face uses 8-bit PNG with transparency. Then you can use a fill color to affect the white/grey areas of the image using grayscale magic.

$ file 1.png
PNG image data, 69 x 109, 8-bit gray+alpha, non-interlaced

I've used just a transparent PNG, without a fill:

$ file runner.png
runner.png: PNG image data, 348 x 250, 8-bit/color RGBA, non-interlaced