Excellent colour rendering, high lumen levels and continuous operation with no degradation in quality

The same can be said for lamps that exceed 6500k in colour temperature as they are too weak in the red end of the spectrum, making reds and oranges appear too similar creating a "washed out" appearance.
The northern sky with a colour temperature of about 7500k and a CRI of 100 is not necessarily the ideal colour rendering light source either. An ideal light source for colour rendering will have both a colour temperature similar to daylight (5000K to 6000K) and a high CRI value (>85).

Regardless of whether or not CRI is the fairest measure of colour rendering for luminaires, it is important for specification, compliance and certification purposes. The US Department of Energy’s Energy Star program, offers generous manufacturer and consumer enticements for developing and installing and high-efficiency lighting products. CRI is one of the criteria , so you need to ensure you address CRI and efficacy issues at design time. For example, to be Energy Star listed, kitchen luminaires and portable task lamps need a CRI of 80, outdoor pathway lights and ceiling down lights require a CRI of 70.