on my part, these make sense, but the first one is somewhat weird.( but no error in grammar.)

I'd only use: "My life was colorless until I saw you" [colourless in British English]. "My life was meaningless until I saw you". ---- If you were to use "insignificant" or "inconsequential" it would give a different meaning: it would be more like saying that you were a worthless person before you met someone. Somehow it doesn't sound quite right though, even though I can see why it would make sense to a non-native literally. The other two suggest that a "special someone" gave your life "meaning" after you met them. They gave you purpose and direction. They sound much better.