Cut the springs down a few mm on the browns and they're lighter to actuate.
Or, you could possibly find replacement springs. That's the other option.
The springs in MX switches are compressed quite a bit when the key is not pressed (I think about 5-7mm or so). By cutting the spring a little, the actuation force is decreased, since the spring is compressed less. Doing this has less of an effect on the force required to bottom out than on the actuation force. I have yet to do this modification on a whole board, since I've been hoping to find replacement springs instead. I have a feeling that cutting the springs will have an adverse effect on their durability. If I could find springs with the same specifications as the originals, except shorter, I think that would be ideal.