Using red as the dominant color on a product immediately defines the characteristic of the product and somewhat makes it feels more predictable as opposed to using it just as an accent color which can create a more vibrant sense and offers that unique "element of surprise". Most of the time the usage of red as an accent color carries a message or meaning. For instance, a red ring element can be found on all Canon L series lenses, which is the professional line lenses from Canon, in this case the use of red accent color is to distinguish and emphasize the quality of one particular line to another. It is considered as unpredictable because red represents both the devils and the cupids, love and anger, blood and fire, and romance and malice. The impressions it creates all depends on the situation, and context is everything. The application of red on black makes the red vibrantly glows and resonate the spirit of adventure, endurance, advancement, and superiority. Red and black is also often associated to masculinity. In the contrary, red on white does not look so vibrant but rather more quiet and elegant, the combination of lighter color and red in some cases also creates the impression of femininity, luxury (especially when red is paired with chromatic elements), and gracefulness (when it's used to accentuate the fluid and elegant curves of the product).
Weather it's red on black, red on white, or red on other colors, using this second most vibrant color (after yellow) as an element to compliment the dominant color always creates that nice and unique "cherry on top" feel.
