Candle
The thinking candle — study, speech, and remembering what you meant to say.
These are associations the community holds, not settled fact — the more a reading is shared, the bolder it sits.
Yellow is the air colour in most modern tables: thought, speech, study, memory, and the confidence to use them in front of other people. The planetary assignment splits — many lists give it to Mercury for the mental work, others to the Sun for the obvious reason that yellow is what the sun looks like. Agrippa's scheme accommodates both, which is how the disagreement started.
The work is unglamorous and genuinely useful. Practitioners light yellow for exams, for a difficult email, for interviews, for the sort of conversation that has been rehearsed for a week and still needs saying. Where red supplies nerve, yellow supplies the words, and most difficult moments need both.
It also does well as a working-hours candle: lit while studying, put out when the session ends, relit next time. That treats the candle as a marker of attention rather than a battery, which is how a good deal of candle practice functions anyway. White substitutes; orange where the thing needs pushing rather than thinking through.
Readings practitioners have offered, ordered by how many recognise them. Take what serves, leave the rest.
Carried forward
Heinrich Cornelius Agrippa, Three Books of Occult Philosophy (1533)
Agrippa gives Mercury the mixed and shifting colours and the work of speech, writing and reckoning. His lamps are not decorative — the light is the point of contact, and the colour is how you tell the planet which one you meant.
Carried forward
Common in contemporary practice
Lit at the start of a study session and put out at the end, so that the candle marks working time rather than powering it. People who use it this way tend to report the effect is on their attention, and are content with that.
Credit what you carry. Much of this comes from living traditions, and some of it from traditions that are closed — held by particular peoples and not offered for general use. Where you know whose practice a reading came from, name them; where you don't, say that too.