@RainGnyu You've probably already started grinding kills, but do yourself a favor and make a note of how many kills you have at the Visphone under achievements. There's no other way to track how many kills you have left besides manually tracking it via the number there. Anyway, here's my two cents on farming kills for your camo:
If you're not sick of cradle yet, you can do more of that. You already know how many mobs that place throws at you if you're lucky enough to get a good long PSE. Drawn to Darkness is a decent alternative to cradle. It has a lot of mobs, but no chance for PSE.
Other than that you can spam Haru TA over and over, which is 100 mobs per 2-3 minute clear. If you have the option, I suggest streaming something on your other screen while you do this.
Some of the recommended quests (the buster one and the mothership one) are OK options too if you want to do something different to mix things up. They're not as efficient as cradle or Haru TA though.