Anything more than a all round white light on a kayak will cause more accidents than it prevents. As they are so narrow it will be possible to see both lights at the same time and confuse boaters as to which direction its moving. Plus it will make them think its a powered boat and will be moving quickly.
The other downside is that as they are so low on the water the lights disappear into the shore clutter.
Maybe you should also have a chat to the dumbass tinny jockeys who love to travel around at night at speed without any lights.