Choose better color palette for highlighting fields

[taviso]

I picked alternating blue and white to highlight fields, but I should experiment and find a better color palette.

Note to self: it's easy to add this, just choose some colors and add them to this array, they'll automatically get added to the rotation.

static HEM_BYTE ColorMarkers[] = {
    MKCOLOR(HEM_WHITE, HEM_LIGHTBLUE),
    MKCOLOR(HEM_LIGHTBLUE, HEM_WHITE),
};