message: DisplayParams initializes its ColorDef to named colors - can't later do
  setFrom() because the named colors are frozen.
diff: @@ -29,8 +29,8 @@ export class DisplayParams {
  public readonly material?: Material; // meshes only
  public readonly gradient?: Gradient.Symb;
  // ###TODO: public textureMapping: TextureMapping; // only if m_material is null (e.g. gradients, glyph bitmaps) // TextureMapping doesn't exist yet!!!
  - public readonly lineColor: ColorDef = ColorDef.white; // all types of geometry (edge color for meshes)
  - public readonly fillColor: ColorDef = ColorDef.white; // meshes only
  + public readonly lineColor: ColorDef; // all types of geometry (edge color for meshes)
  + public readonly fillColor: ColorDef; // meshes only
  public readonly width: number = 0; // linear and mesh (edges)
  public readonly linePixels: LinePixels = LinePixels.Solid; // linear and mesh (edges)
  public readonly fillFlags: FillFlags = FillFlags.None; // meshes only
  @@ -39,31 +39,30 @@ export class DisplayParams {
  /** Instantiates the class based on DisplayParamsType and GraphicParams. */
  private constructor(type: DisplayParamsType, gf: GraphicParams) {
  this.type = type;
  - this.lineColor.setFrom(gf.lineColor);
  + this.lineColor = gf.lineColor.clone();
  switch (type) {
  case DisplayParamsType.Mesh:
  this.material = gf.material;
  this.gradient = gf.gradient;
  // ###TODO: set texturemapping if m_material is undefined, and base it on gradient
  - this.fillColor.setFrom(gf.fillColor);
  + this.fillColor = gf.fillColor.clone();
  this.fillFlags = gf.fillFlags;
  this.width = gf.rasterWidth;
  this.linePixels = gf.linePixels;
  break;
  case DisplayParamsType.Linear:
  - this.fillColor.setFrom(this.lineColor);
  + this.fillColor = this.lineColor;
  this.width = gf.rasterWidth;
  this.linePixels = gf.linePixels;
  break;
  - case DisplayParamsType.Text:
  - this.fillColor.setFrom(this.lineColor);
  + default: // DisplayParamsType.Text
  + this.fillColor = this.lineColor;
  this.ignoreLighting = true;
  this.fillFlags = FillFlags.Always;
  break;
  }
  - // otherwise, generic DisplayParams; keep default property values.
  }
  /** Creates a DisplayParams object for a particular type (mesh, linear, text) based on the specified GraphicParams. */
  