Fix cross marker visibility: update colors and properties for improved contrast on white backgrounds

(cherry picked from commit b697657)

Author: PierreRaybaut

datalab/config.py

@@ -508,8 +508,24 @@ def reset():
         "selected_curve_symbol/alpha": 0.3,
         "selected_curve_symbol/size": 5,
         "marker/curve/text/textcolor": "black",
-        "marker/cross/text/textcolor": "black",
+        # Cross marker style (shown when pressing Alt key on plot)
+        "marker/cross/symbol/marker": "Cross",
+        "marker/cross/symbol/edgecolor": MAIN_FG_COLOR,
+        "marker/cross/symbol/facecolor": "#ff0000",
+        "marker/cross/symbol/alpha": 1.0,
+        "marker/cross/symbol/size": 8,
+        "marker/cross/text/font/family": "default",
+        "marker/cross/text/font/size": 8,
+        "marker/cross/text/font/bold": False,
+        "marker/cross/text/font/italic": False,
+        "marker/cross/text/textcolor": "#000000",
+        "marker/cross/text/background_color": "#ffffff",
         "marker/cross/text/background_alpha": 0.7,
+        "marker/cross/line/style": "DashLine",
+        "marker/cross/line/color": "#A11818",
+        "marker/cross/line/width": 1.0,
+        "marker/cross/markerstyle": "Cross",
+        "marker/cross/spacing": 7,
         # Cursor line and symbol style
         "marker/cursor/line/style": "SolidLine",
         "marker/cursor/line/color": "#A11818",

doc/release_notes/release_1.00.md

@@ -4,8 +4,9 @@
 
 ### 🛠️ Bug Fixes since version 1.0.2 ###
 
-**Annotation visibility:**
+**Marker visibility:**
 
+* Fixed cross marker (shown when pressing Alt key on plot) colors inherited from PlotPy being too pale on white background, and other marker properties explicitly configured for better contrast
 * Fixed default annotation colors inherited from PlotPy being too pale on white background - segment and drag shape annotations now use brighter green (`#00ff55`) for better visibility
 
 **Macro panel layout:**