The Color of Sound
After the sound has been detected by your ear, you will hear the color and texture somewhere in your brain even if you can't at this time describe both. This means your hearing system will actually develop the ability to recognize the color, texture, and shape based on the harmonic function of the chord.
Circle of Fifths
In the circle, the notes we use are arranged so that as you go clockwise around the circle, the notes are a musical fifth apart. The note "C," is usually placed at the top. The fifth note of the C scale (major or minor) is G, so that is next. D is the fifth note of the G scale, and so on. Likewise, C is the fifth note of the F scale (major or minor), so F is one position counter-clockwise, and F is the fifth note of the Bb scale, and so on. The C major scale only uses the white notes on a piano keyboard, the G and F scale each use one black key (for the G scale, it is a "sharp" and for the F scale a "flat"). With each step farther from C, an additional black key is added.
On the inside of the circle is the relative minor scale. That is, the "a minor" scale uses the same notes as the C major scale, only it starts on the note A.