Not necessarily, if anything I think it would be a sign of a macro nutrient deficiency.
What kinda plant, and pics at all? Also, how is your lighting and the rest of your tank specs?
Just because nobody answered this question: yes, replace the 'unidentified bulb' with a 6500k bulb and you'll be off and running. I have plenty of success with 6500k/10000k running in tandem.