Neon yellow is the default highlight color in excel, so that probably has more to do with it's usage. Generally don't wish to alarm people with my work, so use soothing colors for their benefit as well as my own. Some people don't realize the impact of color. A co-worker had her email set to red text for unread messages; it may have even been the default but can't remember. Told her that her inbox looked very alarming and emergent. She changed it and then later noted to me, it was much less stressful to look at.