You can get pretty much any Kelvin rating in any PC that you can get in a standard T-5, T-8, & T-12 bulb.
If you want a "plant" bulb, you really want something in the red wave lengths. Those wave lengths would be anything in the 5000K - 6500K range. Your "white" lights tend to be in the 10000K-18000K range and do little to facilitate plant growth.
The plant bulbs color will tend to look yellowish compared to the higher Kelvin ratings. If you want to use a plant bulb, yet have a color enhancing properties, add a actinic bulb. Adding the blue, in addition to the plant bulbs will actually give you a color closer to the "white" light, yet still produce the plant friendly wave lengths.