Final answer:
The description of the art style in the question most closely resembles Impressionism, but the characteristics can also apply to other movements such as Post-Impressionism, Fauvism, and Art Nouveau, making the statement somewhat inaccurate.
Step-by-step explanation:
The description of art featuring pastel colors, scenes set outside, being generally upbeat, and depicting common everyday subjects most closely aligns with the characteristics of Impressionism. While Impressionist art was known for its use of light colors, en plein air settings, and everyday subject matter, the description provided does not specify enough detail to identify a single art style categorically. True, the statement could be associated with Impressionism, but aspects such as thick paint application, geometric forms, or the use of symbolic or unnatural colors can also be linked to Post-Impressionism and movements like Fauvism and Art Nouveau. Therefore, the assertion in the original statement cannot be considered fully accurate without more context, as the styles of the late 19th to early 20th century varied greatly.