Ok, 7x7 = INSANE!
But, also doable. ;) ;)
Although it would need more black to separate the 3 sides.
I think I like a smaller number of tiles better - to me it really looks like the cube. And it wouldn't be to hard.
It's all 60 degree diamonds - a gazillion ways to make those. And you can either outline each diamond in black or piece the larger diamonds, and then use that black fusible stuff that comes coiled - I'm drawing a blank right now :roll: - that's used in celtic quilts or for the stained glass look- to cover the seams.