Laser Harp...?

[Snipeye]

Hey, guys - I'm an electronics enthusiast, and for my next project I've decided I want to tackle a laser harp. I've started working with some glycerine for fog to get the beams to show up, and I could kinda/barely see a little red laser pointer (build into a $3 toy, so I'm guessing ~5mW, if that) with the fog I used, but I'm looking at possible an RGB laser for the actual harp so I can control the color a lot more precisely. I'm hoping for the final build to be <$100, which is quite ambitious, I know - but my questions is what sort of wattage it takes to get a laser to show up in fog, and how much color plays a role in that? I will possibly have a TV on in the room - if I can, I want to make a "laser harp hero" game - so I know that's gunna make a big difference. What are your thoughts on these lasers - that is, how will actual power output compare to advertised, and how well will it show up? Not going for super long-distance accuracy here.

RGB 200mW Laser Module White Laser Beam Combined by Red Green Blue Laser | eBay

Lab 532nm 100mW Green Laser Module 660nm 200mW Red Module with Driver Board TTL | eBay

Thanks, guys!

 

[Snipeye]

EDIT/NOTE:

OK, I set aside a couple hours and really read through a lot of stuff and watched videos, etc. I'm guessing I want something closer to the 30mw range, and probably just using 532nm will be best for visibility.

Is that a reasonable assumption? If so, where's a good place to buy something that'll be definitively about 30mw? I've seen several recommendations for places to buy lasers, but they seem to be geared to higher-powered lasers (100mw+) and that's definitely not what I need - I don't want to be burning people's hands as they try to play. Also from what I hear, ebay's not the place to do it as they may come extremely over or underspec, neither of which is desirable. I don't really care about power usage - this is going to be inside, plugged in, so it has all the power it needs, but I'd like something precisely... bright, but safe to touch. Is 30mw a good estimate for that?

Thanks guys!