Collectible Card Game Headquarters

Describe the Bug:
Engineered Explosives asks for G mana when you select W from the prompt.

Which card did behave improperly ?
Engineered Explosives

Which update are you using?(date,name)Which type(Duel,Gauntlet,Sealed Deck)
BNG v2

What exactly should be the correct behavior/interaction ?
W = W

Are any other cards possibly affected by this bug ?
NA unless this is a sunburst problem in general?

Has been rewritten since BNGv2.

If you select the mana before you cast it it works fine. But if you try to cast Engineered Explosives with an empty mana pool and then use mana sources that can produce >1 color of mana you never get asked what color to produce and Engineered Explosives never gets more than 1 counter.

I'm hesitant to call this a bug - the documented interface is to not harass the human player with a color choice if he's paying a generic mana cost - but I've put in a hack to force an explicit color choice while paying for this and other sunburst cards in e560104.