I have already posted this problem at Unity Answers, however I haven’t had any luck there. Maybe, someone can help me here.
I have a plain white-textured sprite with Sprite/Diffuse material on it. I added a spotlight on the scene to achieve this effect:
It works fine in the Editor and Webplayer.
However, in my Android build, I get this instead:
I already tried setting the Quality Setting to “Fantastic” but I still get the same effect. Any suggestion guys?
Original post.
When going to File → Build Settings, try changing the Texture compression. Also try to check “Use 32-bit Display Buffer” and/or “Use 24-bit Depth Buffer” in the Android Player Settings (“Player Settings…” button in the build settings panel, then the android icon and in the Resolution and Presentation section).
Can’t tell for sure this will help but you can always give it a try 
Thank you for the response. I tried that as well. Tried all possible compressions (compressed, 16bits, truecolor) and filter modes (point, bilinear, trilinear). Still doesn’t solve the problem… I have already tried it on 3 different android devices, Note, S4, S3-like model (not sure what it is).
When I said “Texture compression” I meant: DXT (Tegra), PVRTC (PowerVR), ATC (Adreno), ETC1 or RGBA16 (GLES 2.0) that you can choose in the Build settings window 
Maybe you tried that already but that’s the last thing I can think of…
