I can't count the number of times I've heard a bass player say about tone: "it's all in your hands", or something to that effect. It is true that you can vastly later your bass tone using different hand positions, techniques, and touches. I made a lesson on that:
However, it's also true to say that what strings you use, the actual instrument you choose and the amp/effects you use has, arguably, an even bigger part to play.
Study the great players, listen to loads of music, and work out what your favourite player is using. This will all help in you finding the perfect bass tone for you and your situation. Perfect may be too strong a word. I like having a few different basses as I record a lot in different styles.
Hear those basses on my remote bass recording session website.