As far as I know, the order of iteration over tables after the array part is not-specified, so
{Transparency = 0.5, Color = Color3.fromRGB(255, 255, 255)}
is the same as
{Color = Color3.fromRGB(255, 255, 255), Transparency = 0.5}
as far as luau is concerned. You could just say “screw ordering”, but unless you make a cop-out for the Parent property, that could have large (and easily avoidable) performance implications.
Also, …why? You have to type out a couple more letters in your autocomplete-having IDE?
Having all a part’s properties coerced onto one line is not very nice in my opinion, and it becomes more difficult to discern which properties are being set. Of course, you could write it out over several lines:
local newPart = Instance.new("Part", {
Anchored = true,
Position = Vector3.one,
Orientation = Vector3.new(45, 0, 0),
Transparency = 0.5,
Color = Color3.fromRGB(255, 255, 255),
Parent = workspace})
But I feel like I’ve seen this before…
Edit: Also, we had this before, and it was not good.