Whatever colour temperature you use, one of the most important things about the light is the color rendering index (CRI). This measures how good the light is to properly display the real colour in comparison with natural light. The higher the CRI, the better it is. 

Warm colour temperature is yellowish white (2600K to 3200K), cool white is 3200K to 4500K and daylight is above 4500K. Office lighting generally uses cool white.

Daylight white and cool white have a bluish and very bright tint to them, perfect for offices. 

It should be noted that colour temperature above 4000K is also useful for alertness, whereas warm white has a calming effect.

Most of the lights I put in offices are now tri-colour which means you can choose if you want warm white, cool white or daylight. That way the customer or end user has complete control over the colour temperature, and can adjust it to different products, rooms etc.

The colour rendering index (CRI) is measured between 0 and 100 and shows how true a light is at displaying true colours relative to a natural light. In the office, I would recommend that you should get a light at least CRI of 80 otherwise the colours will looked washed out.

The generally accepted assumoption is that the best colour temperature for offices is somewhere between 3500K and 5500K. The reason for that is that under 3500K will be too warm and not alert enough; but above 5500K is too blue and too crisp.