Cool white, even the old Luxeon green and stark blue/purple has never kept me from getting work done, including fiber splicing. That being said, my general preference s are 4000k, neutral ,for general use and 2700 to 3000k, warm ,for nighttime, total darkness, etc,etc.
ezdog, Milwaukee is producing some really nice work lights for sure! badwolf, the little 5mm led is now available from Yuji manufacturing in high CRI and 3200K. They are great for modding! Really nice upgrade for Photon Freedom and similar coin cell pinch lights and the like.One supplier, not affiliated in any way, other than a retail customer http://www.mtnelectronics.com/index.php?route=product/product&product_id=954&search=YujiThese are not good at distance, but make wonderfully even, floody beams.