To answer these questions you need to devolve to the mind of a law enforcement officer. The airsoft guns look real. Even if you gave your kid a bright orange and then he painted it black or blue there are potential problems. If you are carrying one in public, in many communities, mostly large cities in the USA, you could in fact be charged with bandishing a weapon if you are showing one off to your friends. It is the paradox of making a harmless toy look real. In the mind of a law officer you are placing yourself at risk to defend the helpless and any potential deadly threat can be cause for action. If you live in a rural area then the risk is much less.
If you own these lifelike airsoft toy guns keep that in mind as you play.