The candles for St Expedite always have to be red? Are also valid tea candles?
There is an aspect I do not understand, it is the time the candles should be burning. It is a great candle continuously burning for 7 days and nights, or only you light it for a while every day for some minutes while you pray and then blow the candle out until next day?
I have read that St Expedite rituals should be only in wednesday?
Generally, if a candle colour is suggested for a spirit, then yes, the candles should be that colour. While not absolutely mandatory, such correspondences do help to make contact with the spirit.
The same thing goes for the day of the week. It is preferable to perform the ritual on Wednesday, but if its an emergency and you can’t wait, the spirit can be still be petitioned.
And yes, tea candles can be used.
A 7 day candle should be left burning daily for as long as possible. Of course, proper fire safety should be adhered to and the candle extinguished any time you are not present to watch over it (which means when you leave the house and when you sleep. Never, ever, fall asleep while a candle is lit).