Hi rosa, i usually just blag my way out of using red flowers for summer weddings because of the very reason you have given! I say all white in the churches as it "stands out better than red from a distance" and table arr use greenery to lighten the arrangements along with red roses. It does depend on the red rose though, grand prix roses you can get away with burgandy flowers and passion roses blood red flowers. really just using the same usual suspects in red for arrangements if you really have to ie gerbs, roses, anthuriums, alstro etc and using pretty summer greenery to make it look more summery ie fountain grass, wiegelia, etc