The relative importance of color will vary within sectors and product categories but color (or even its relative absence) is usually a key and multi-faceted signifier among the elements that combine to build core a brand identity—as well as in your supporting marketing materials, sales tools, and certainly in products themselves.

Not giving it due consideration before deploying a major campaign will definitely not help you differentiate yourself visually and may affect both brand perception and resulting sales.

And, it can be counterintuitive: color in fashion, especially at the high-end, is often less important in core branding elements (logos, for example tend to be monochromatic, classic marks) but is vital in seasonally differentiating products such as a clothing collection and or accessory line which is also reflected in ad campaigns. But there are always exceptions: http://us.christianlouboutin.com/ is known as much for the red sole as for the ever changing shoes they are attached to. The red of the sole is visible from a much longer distance, and multiple angles. than the logo, itself.

If I say John Deere, you will think of a color; if I say Caterpillar you will think of another. Companies will fight tooth and nail to embed specific color triggers into our connection to them and protect such color as part of their intellectual property. Evidently, they think color deserves much consideration.