Apart from a few exceptions, hiking off-trail in the Negev is prohibited and potentially dangerous. All of the established trails are well-marked in a uniform system that applies all around Israel.
There are four common colors for local trails; Blue, Green, Red and black.
A triple-color marker indicating sections of the Israel trails:
The colors do not indicate difficulty, just different trails. As a rule you should always be able to see the next marker if you are standing on a marker, which means that if you can’t see a marker- GO BACK TO THE LAST MARKER. Do not continue forward in hope of re-connecting with the trail. Turns and trail crossings are marked with special markers.
Hiking at night is only allowed on specific trails, so make sure to plan your hike to end before dark.