Yes the vividness will get better, and once you become lucid in a drem, try shouting out "more vividness", but make sure you're fully stabalized first, or else the vividness might be too much and you'll slip out of lucidity.
The reason they aren't as vivid as real life is because your mind generates dreams, so they won't always be the clearest. However, many people have had dreams as vivid as real life, it just takes practice.
Good luck and happy dreaming!