While not a mod or recast, I recently finished a prototype for an illuminating wand.
I was not aware of the Dot Star Micros at the time, but they seem like a good option for color options and I'll definitely try them in the future when I look into color mixing.
If your goal is to have it as bright as possible, though, I do have some recommendations.
I don't have my parts list with me at this time, but here's a link to digikey with one of the LED's I found works really well.
https://www.digikey.com/products/en?keywords= LUW CR7P
Those are not the brightest on the market, but I'd bet they would be strong enough for your project.
In general, what you're searching for is a surface mounted (SMD) 5000-6000K, high current LED of about 100 Lumens and roughly a 3x3 mm square profile. This will allow it to sit unaltered inside a 5 mm diameter. You could possibly go as big as 5x5 and file down the corners slightly (I successfully tested this for the 3x3 mm ones) but that is a very risky thing to do with components this fragile.
My plan is to make a build thread for my own design in a bit, but if you have any questions about the leds I can answer here as far as my knowledge allows.