Keep the colors between drawing multiple scribbles and arrows (#61)

* Keep the colors between drawing multiple scribbles and arrows

The color is changed back to black on every new drawing. Now the color is kept. If there is no color is set, then there is a fallback to the black stroke as before.

* requested changes
Co-authored-by: togir <gitcatch@weiler.rocks>

public/javascripts/spacedeck_whiteboard.js

@@ -592,7 +592,8 @@ function setup_whiteboard_directives() {
         z: z,
         w: 64,
         h: 64,
-        stroke_color: "#000000",
+        // Set the color to the last selected color, fallback to black if no color was selected
+        stroke_color: "#" + $scope.color_picker_rgb || "#000000",
         stroke: 2,
         shape: "scribble"
       };
@@ -629,7 +630,8 @@ function setup_whiteboard_directives() {
         z: z,
         w: 64,
         h: 64,
-        stroke_color: "#000000",
+        // Set the color to the last selected color, fallback to black if no color was selected
+        stroke_color: "#" + $scope.color_picker_rgb || "#000000",
         stroke: 2,
         shape: "arrow"
       };