Based on the comments of the accepted answer on this question Is there a spell that can create a permanent fire? and after doing a search for half an hour I couldn’t find an answer.
My scenario: I want to create a PC that does not have darkvision but wants to have a constant source of light. It is a cleric that wants to put the Continual Flame on his shield. He doesn't want the Darkness spell to dispel the expensive spell on his shield so he upcasts it to 3rd level so that he can see in the darkness spell and in regular darkness as well.
Darkness (PHB page 230):
Magical darkness spreads from a point you choose within range to fill a 15-foot-radius sphere for the duration. The darkness spreads around corners. A creature with darkvision can’t see through this darkness, and nonmagical light can’t illuminate it. If the point you choose is on an object you are holding or one that isn’t being worn or carried, the darkness emanates from the object and moves with it. Completely covering the source of the darkness with an opaque object, such as a bowl or a helm, blocks the darkness. If any of this spell’s area overlaps with an area of light created by a spell of 2nd level or lower, the spell that created the light is dispelled.
Continual Flame (PHB page 227):
A flame, equivalent in brightness to a torch, springs forth from an object that you touch. The effect looks like a regular flame, but it creates no heat and doesn't use oxygen. A continual flame can be covered or hidden but not smothered or quenched.
According to PHB page 201:
When a spellcaster casts a spell using a slot that is of a higher level than the spell, the spell assumes the higher level for that casting
If I cast Continual Flame at 3rd level, would Darkness dispel it? Would the flame shine in the Darkness?
Darkness vs Daylight Interactions Accepted answer suggests Continual Flame wins.
Does the Light cantrip cancel out the 2nd level Darkness spell? Accepted answer suggests Continual Flame wins.
Both of those questions and answers touch on this but neither has a solid answer for this scenario.