Acne redness can be tricky when you need to apply your makeup to cover those acne. It is important to ensure good coverage on them. There are two main thing you need to take note. Firstly, will be your choice of concealer. The color. Next, is how you apply your cosmetics concealer makeup.
Color for concealer has to be light but you should not choose too light color. Try to go for one shade lighter than your skin tone. Too light color will not necessary cover acne or your pimples skin. Instead this can highlight your acne blemishes making it more obvious. Always apply concealer before your foundation for eye area and it can be before and after foundation on face but has to be before applying your face powder.
Don't ever rub your concealer when you apply it. Use the dabbing method. Use a concealer brush to apply small amount onto the area that you like to cover acne or blemishes. Use your forth or last finger to even the concealer. Apply dab mode and use your strength gently. Please follow this rule otherwise you will end up losing your concealer over the foundation.
The aim here is to lighten the acne redness and cover acne but not to get rid of the acne or to remove them.
Try viewing this video. Hope it helps.
http://www.youtube.com/watch?v=7teyzhLIaog