Odd Ground ( terrain ) texture appearance

I'm working on an android game, and get t$$anonymous$$s odd behaviour on two different phones after creating the build (apk) . (Both show the same odd looking terrain texture, w$$anonymous$$le all the other textures for trees, bridges, etc are looking nice. ) In the editor, with open GL 2.0 emulation on (or without emulation at all) the terrain (is a sand texture) & actually looks like sand. Like t$$anonymous$$s screenshot:

But when running on either Samsung S2 or Gionee M2 phones, the ground texture looks like the right hand picture in the screenshot. (rather blotchy...)

So, I've tried turning off MipMaps from the "sand" texture itself, and tried changing the compression to RGB 16 Bit (Essentially trying to use no compression). Wrap mode is Repeat, with Filter Mode set to Bilinear.

I'm not sure if I'm just checking the wrong settings and it's actually rendering like I've set it to... Here's a screenshot of the settings:

Lastly, in Build Settings, I have "Texture Compression" set to: Don't Overide.

Any thoughts or pointers of what to try/adjust or where to check further would be appreciated, since I'm finished the game, but the sand doesn't look like sand... :)