Here's why:
* "Dial" is a common noun, referring to a device for making phone calls.
* "Colgate" is a brand name, which is a proper noun. However, brand names are generally not capitalized unless they are part of a formal company name (e.g., Colgate-Palmolive Company).
Examples:
* Correct: I dialed the wrong number.
* Correct: I use Colgate toothpaste.
* Incorrect: I used a Dial soap. (Unless "Dial" is part of a specific product name)
* Correct: I work for Colgate-Palmolive.