I need to disagree with you here. If they are decent diodes, such as the Samsung LM301B/H then 3000K for vegging a plant is not a problem at all.
I have done it many times before, used both 3000K and 3500K with excellent results. The amount of blue light a cannabis plant requires is not all that much and 3000K full spectrum still gives enough blue. You can certainly flower with 3000K and 3500K.
As soon as one starts to go 4000K upwards then the light starts to become a bit too specific IMO and leaning more towards a light I'd only want to use for veg. 3000 to 3500K I feel is the perfect combination for veg & flower, also keeping in mind plants are in veg for a fraction of the time they are in flower for (generally speaking, depends on how one runs their grow though).
The kelvin of HID lights might work as you described, although for decent LED diodes 3000K for veg is fine.