1. Peach color: When some peach varieties are fully mature, the flesh may appear reddish or pink. So even if the canned peaches are made of white peaches, the flesh may have some red marks.

2. Additives: In order to increase the attractiveness of products, some canned peach manufacturers may add food pigments, such as red pigment, to enhance the color of products. In this case, the red pigment may cause the canned white peach to look reddish.

3. Acidity: Peaches contain natural acidity. When the pulp in canned peach comes into contact with acidic liquid, its acidity may cause the pulp to change color and appear red or pink.

It should be noted that the reasons I mentioned may not be applicable to all canned white peaches. Each brand and product may have different production processes and formulas. If you are in doubt about the color of a specific product, I suggest you check the formula and production process of the product or consult the manufacturer directly.