Nothing seems to have as much impact on atmosphere as wall color. When walking into a room, a bright, bold color on the wall can instantly startle, stumble, or wake up an individual who was previously lost in a daydream. The formerly frazzled might step into a calming nest of blue walls and feel the heartbeat slow and sense the nerves begin to calm. Psychological attachments or color memories can imperceptibly alter mood, but emotional responses to color vary by person. Research has indicated that warm hues, such as reds and yellows, are perceived as stimulating and are often associated with aggression, strength, courage, frustration, lust, and feelings related to action and assertion. Many of the studies tagging red with this stimulating effect were done in North America, so it's easy to see how the use of red as the color used for fire engines, ambulances, and emergency signs in this region could be attached to a cognitive trigger for a "stimulating" effect. Other areas