While there are a few colors labeled as fluorescent in this range of threads from Sybai, they are all very reactive to UV light, making them great for tying flies that light up even in natural colors. The olive colors make a great alternative to the now-impossible-to-find UTC Watery Olive, which was desirable due to its moderate fluorescence.
This thread is 78 denier, meaning it's nearly the same weight as UNI 8/0 or Textreme 8/0 thread, so thin enough for even small flies down to size 24.
