I am assuming you haven't finalised your wall colours and colours of any other fixed elements. In case you have finalised your color scheme you would need to see which of these colours blend well or complement with that scheme. Assuming none of this info is available, then you could look at the neutrals which go with all colours. The white tile and the 2 colours at the end would be preferable. If you want color on the floor as well as drama, you can choose from the 2nd options from both sides or even the 1st from left.

hi first fix the tile on the ply using epoxy chem leaving groves to be filled later with epoxy grout fix the ply with tiles on celling with fastener and then apply epoxy grout to fill the groves later left

Terracotta tile roof as a truss over the main roof or broken ceramic tile mosaic over the existing terrace

You could go for tiles with design if they are simple ones. if you want plain, you can add some life in the country style with an exposed brick facade or subway tiles. for colours, it depends on how far out of your comfort zone you're willing to go. white is the safe choice, but you can go for blue, green, yellow, all pastel hues