Flashlights with a neutral/warm tint are considered one of the best in terms of CRI. The higher the CRI number the more accurately a flashlight beam shows an objects' true colour. For example, leaves which appear green under high CRI lighting appears washed out by normal cool white tints. 

Some people consider Nichia 219B/219C to be 'perfect' tints, though this is subject to personal preference. The neutral to warm spectrum ranges from 5000K (most whitish) all the way down to 3000K (most yellowish).