local plr = game:GetService("Players").LocalPlayer
local char = plr.Character or plr.CharacterAdded:Wait()

local trail = Instance.new("Trail")
trail.Parent = char.Head

local a0 = Instance.new("Attachment", char.Head)
a0.Name = "TrailAttach"
local a1 = Instance.new("Attachment", char.HumanoidRootPart)
a1.Name = "TrailAttach1"

trail.Attachment0 = a0
trail.Attachment1 = a1

local startColor = Color3.fromRGB(153, 50, 204)
local endColor = Color3.fromRGB(148, 0, 211)
local sequence = ColorSequence.new(startColor, endColor)
trail.Color = sequence

wait(10)

for i = 0, 1, 0.1 do
    trail.Transparency = NumberSequence.new(i)
    wait(0.1)
end

trail:Destroy()