Down Fire Kundalini
For those who do breath infusion (kapalabhati/bhastrika pranayama).
Apart from spinal kundalini which is the traditional understanding of the kundalini with distribution hubs called chakras, there is cell kundalini, which involves each cell having its own kundalini charge which can be expressed into itself or which may burst out to touch cells which are near to it.
Other than that, there is a down-fire kundalini, which is either spinal kundalini or cell kundalini firing itself down into the body instead of up (urdhva). This is positive even though the energy moves downward. This downward movement is purifying and provides light to see down in the dark places. The firing of kundalini downward destroys sluggish pollutions.
When this happens the yogi sees down in the body and realizes the fired kundalini as an energy which is like dangling coils/springs which has a white translucent color and which has a bliss aspect which is like spearmint. This is similar to the chit akash sky of consciousness energy.