Some characts changes color after update

[taktes]

Hello, thank you for such amazing library, I can't even imagine that something like this exists for elixir!

I noticed that when updating the state, the color of some symbols sometimes changes to white, and I don't understand why. Here's an example to reproduce:

defmodule TestUi.App do
  use TermUI.Elm

  alias TermUI.Event
  alias TermUI.Renderer.Style

  def init(_opts), do: %{matrix: generate_matrix()}

  def event_to_msg(%Event.Key{key: :up}, _state), do: {:msg, :up}
  def event_to_msg(_, _), do: :ignore

  def update(:up, state), do: {%{state | matrix: generate_matrix()}, []}

  def view(state) do
    stack(:vertical, [
      Enum.map(state.matrix, fn row ->
        letters = Enum.map(row, fn letter -> text("#{letter}", letter_style(letter)) end)
        stack(:horizontal, letters)
      end)
    ])
  end

  defp letter_style("a"), do: Style.new([fg: :green])
  defp letter_style("b"), do: Style.new([fg: :yellow])
  defp letter_style("c"), do: Style.new([fg: :blue])
  defp letter_style("d"), do: Style.new([fg: :red])

  defp generate_matrix do
    matrix = ["a", "b", "c", "d"]
    Enum.map(1..5, fn _ -> Enum.shuffle(matrix) end)
  end

  def run do
    TermUI.Runtime.run(root: __MODULE__)
  end
end

The program prints a matrix of colored symbols (the same symbol will always be the same color):

Then, when I press key up for update the matrix I got this:

Look at "a" letter in very last row, now its white. Can you explain why it may happen?

[pcharbon70]

Sorry for the very late reply. What version of the library was it?
There is a new version 1.0.0-rc out that may have fixed it but it has some breaking changes.
Otherwise I can have a look at the version you used.