Labyrinthos Grape Lamppost, day vs. night

The default colour of the grapes is Plum Purple, at least that's what it looked like to me when previewing dyes (I did not dye mine).

Glade Pendant Lamp can be bought for 3,000 Gil from housing vendors, it can be crafted, or if you own a residence in Gridania your place may have come with one or more.

Beeswax Candles can be bought for 45 Gil each, 360 Gil for every 8 you need, from Material Suppliers in housing areas; vendor NPCs you place in your residence don't sell them.