Style: Attenuated default opacity of ImGuiCol_Separator in Classic and Light styles.

docs/CHANGELOG.txt

@@ -45,6 +45,7 @@ Other Changes:
 - Window: Fixed InnerClipRect right-most coordinates using wrong padding setting (introduced in 1.71).
 - Word-wrapping: Fixed overzealous word-wrapping when glyph edge lands exactly on the limit. Because
   of this, auto-fitting exactly unwrapped text would make it wrap. (fixes initial 1.15 commit, 78645a7d).
+- Style: Attenuated default opacity of ImGuiCol_Separator in Classic and Light styles.
 - ImDrawList: Fixed CloneOutput() helper crashing. (#1860) [@gviot]
 - ImDrawList::ChannelsSplit(), ImDrawListSplitter: Fixed an issue with merging draw commands between
   channel 0 and 1. (#2624)

imgui_draw.cpp

@@ -260,7 +260,7 @@ void ImGui::StyleColorsClassic(ImGuiStyle* dst)
     colors[ImGuiCol_Header]                 = ImVec4(0.40f, 0.40f, 0.90f, 0.45f);
     colors[ImGuiCol_HeaderHovered]          = ImVec4(0.45f, 0.45f, 0.90f, 0.80f);
     colors[ImGuiCol_HeaderActive]           = ImVec4(0.53f, 0.53f, 0.87f, 0.80f);
-    colors[ImGuiCol_Separator]              = ImVec4(0.50f, 0.50f, 0.50f, 1.00f);
+    colors[ImGuiCol_Separator]              = ImVec4(0.50f, 0.50f, 0.50f, 0.60f);
     colors[ImGuiCol_SeparatorHovered]       = ImVec4(0.60f, 0.60f, 0.70f, 1.00f);
     colors[ImGuiCol_SeparatorActive]        = ImVec4(0.70f, 0.70f, 0.90f, 1.00f);
     colors[ImGuiCol_ResizeGrip]             = ImVec4(1.00f, 1.00f, 1.00f, 0.16f);
@@ -316,7 +316,7 @@ void ImGui::StyleColorsLight(ImGuiStyle* dst)
     colors[ImGuiCol_Header]                 = ImVec4(0.26f, 0.59f, 0.98f, 0.31f);
     colors[ImGuiCol_HeaderHovered]          = ImVec4(0.26f, 0.59f, 0.98f, 0.80f);
     colors[ImGuiCol_HeaderActive]           = ImVec4(0.26f, 0.59f, 0.98f, 1.00f);
-    colors[ImGuiCol_Separator]              = ImVec4(0.39f, 0.39f, 0.39f, 1.00f);
+    colors[ImGuiCol_Separator]              = ImVec4(0.39f, 0.39f, 0.39f, 0.62f);
     colors[ImGuiCol_SeparatorHovered]       = ImVec4(0.14f, 0.44f, 0.80f, 0.78f);
     colors[ImGuiCol_SeparatorActive]        = ImVec4(0.14f, 0.44f, 0.80f, 1.00f);
     colors[ImGuiCol_ResizeGrip]             = ImVec4(0.80f, 0.80f, 0.80f, 0.56f);