The majority of people subconsciously associate "hammer" to the concept of tools, and "red" to the concept of color. The math problems early on forced you to focus on calculating, so when you were asked to name a tool and a color, you answered with your immediate subconscious reaction.
If you came up with "red hammer", then your associations match what is prevalent in our culture. If not, then you're one of the few people with a slightly different brain. Share this with your friends and see what they come up with!