There is no specific color that is universally recognized as giving peace of mind in the USA or any other country. However, certain colors are known to have calming and soothing effects on the mind and body, such as blue, green, and lavender.
Blue is often associated with calmness, tranquility, and relaxation, and is believed to reduce stress and anxiety levels. Green is also known to have a calming effect, as it is associated with nature, growth, and balance. Lavender is a light shade of purple that is often used in aromatherapy and is believed to promote relaxation and reduce stress.
However, it's important to note that color preferences and their effects on mood can vary from person to person, and cultural background and personal experiences can also influence individual perceptions of color.