private static Color tweenColor( LTDescr tween, float val )
{
Vector3 diff3 = tween._optional.point - tween._optional.axis;
float diffAlpha = tween.to.y - tween.from.y;
return new Color(tween._optional.axis.x + diff3.x*val, tween._optional.axis.y + diff3.y*val, tween._optional.axis.z + diff3.z*val, tween.from.y + diffAlpha*val);
}