message: make linearcolor public
diff: @@ -486,7 +486,7 @@ impl From<Color> for [f32; 4] {
  /// A RGBA color in the *linear* color space,
  /// suitable for shoving into a shader.
  #[derive(Copy, Clone, PartialEq, Debug, Serialize, Deserialize)]
  -pub(crate) struct LinearColor {
  +pub struct LinearColor {
  /// Red component
  pub r: f32,
  /// Green component
  