Arnt these just dark planets, and rightly so.
If you cannot see stars then something is in the way
Hmm... No. Take any system in Odyssey (4.0), target preferably a gas giant an watch the bright dots on the skybox wander off from your target reticle until they magically disappear and sometimes jump around before disappearing. Your target will reappear just when you are close to it. Also magically...
Now switch to Horizons (3.8) and do the same... you'll notice the difference immediately...