Foundation appearing red? It has everything to do with the base formula. Foundation shades are created out of shades of orange. This is why foundations appear brown in the bottle, but show as orange, peach, or red on the skin. Cosmetic chemists use red, yellow, black, and white pigments to get as close to your skin tone as possible. Blue, green, and purple pigments are often not used because of budgeting reasons or because they easily distabilize a formula.
Now why would we want to use blue in our foundations? The answer is color correction. Blue can neutralize the orange tone that shows up on the skin. Green can neutralize red undertones, and purple can help tone down very yellow foundations.
Ultramarine Blue is the main pigment used to correct shades but gives off a sulphur smell when placed in formulas with a ph of six or higher. People who make bath bombs know this smell too well! By using ph adjusters, they may interact poorly with other ingredients in the formula, namely emulsifiers (the ingredients that help water and oil mix) and preservatives. To keep the product in top shape, many companies forgo using color correction.
Another reason for the red undertone is the high percentage of base fillers used in the formula. These white colored powders can alter the look of a shade making the undertone more pronounced. You may have noticed this phenomenon when you purchased the same shade name in a different foundation product made by the same company. Formulas with titanium dioxide in their active ingredients list for sunscreen can also cause foundations to add a pink hue to the skin.