Go through the entire alphabet, envisioning each letter, observing the color it appears to you in your mind and writing it down.
Iyani phanda nga ha mavhala a nngwe ni tshi tansavhudza mafurase ane kha dziphara ni tshi amba zwothe zwe a amba kha muhumbulo muthihi na u zwi tikedza unga muhumbulo.