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.
With only one bright color, the after image is usually not bothersome, but with two bright colors together, the afterimages interfere with one another, causing a visual vibration. This can be reduced by placing a neutral color between the two areas of bright colors or by making one of the colors a pastel or dark shade. Some Vibrating Color Combinations (Avoid) Below are some color combinations that can cause afterimage effects. Note: It is possible for some of these combinations to pass minimial WCAG contrast tests. However, some users may find the pairing uncomfortable.