If the gifts are deductible, the actual cost of the donation is reduced by your tax savings. For example, if you are in the 33% tax bracket, the actual cost of a $100 donation is only $67 ($100 less the $33 tax savings). As your income tax bracket increases, the real cost of your charitable gift decreases, making contributions more attractive for those in higher brackets.
Small particles of dust and pollution in the air can contribute to (and sometimes even enhance) these colors, but the primary cause of a blue sky and orange/red sunsets or sunrises is scattering by the gas molecules that make up our atmosphere.
1) The temperature at noon is warmer than at sunrise and sunset 2) The sun itself is red at sunrise and sunset, but is yellow at noon; it has nothing to do with the effect of the atmosphere 3) Red light is easily transmitted through the air since its frequency is the lowest.