Final answer:
Lindsey used a monochromatic color scheme for her bedroom, which consists of different shades and tints of a single color, in this case, blue. Option B is correct.
Step-by-step explanation:
Lindsey decorated her bedroom using different shades and tints of blue. The color scheme she used is B) Monochromatic colors.
A monochromatic color scheme involves the use of variations of a single hue, which in this case is blue. This approach is known for creating a high level of unity and harmony in design and artwork, as all the tones relate to each other. Monochromatic color schemes can be seen in works like Monet's 'Houses of Parliament, London', where different shades and tints of one color provide depth and dimension to the piece.
Hence, Option B is accurate; Lindsey designed her bedroom using a monochromatic color scheme, incorporating various shades and tints of a single color, specifically blue.