isColor() on 3.6

[greenhut]

Although color was introduced in 3.6, isColor() was well... forgotten. I checked with rim support cand they confirmed there is no way to check for color on a 3.6 device, nor were there any known workarounds.

I figured out a workaround that is somewhat brittle, but it's ok now.

All B&W devices have Horz res < =160, so:

if (graphics.getScreenWidth() > 160)

is effectively isColor... until they release a low res color watch...