Yes, it's blue because it reflects blue.

Twisting of words there. Because it appears blue, conventionally we call it blue, even though the thing itself is anything but blue. That it appears blue ironically means it is not blue.

On the contrary, you're the one who's defining something being blue as the opposite of what it is. Things are the color they reflect, not the color they absorb. A thing that reflects blue is blue, how could it be otherwise?

The things are not the color they reflect, in the same way your position does not include the ideas that you reject, and the rubber ball that reflects off a wall is not that wall itself. Things are the color that they are, whether perceptible or not, but the color that is reflected eliminates that possibility for the thing's actual color.

Why are things the color they absorb?

You are what you eat.