Just got a new Tab A7, which replaces an older Tab A; the former was set up identical to the latter by using SmartSwitch. Both are locked by PIN. On the older tablet the screen darkens when the PIN prompt is displayed, thus making it stand out against a light background; on the new tablet this does not happen, which makes the PIN prompt hard to distinguish against a light background. I cannot find anywhere to change either the PIN prompt background or the PIN prompt itself (e.g., font size and color). Is this possible?