diff --git a/windows/colorbutton.cpp b/windows/colorbutton.cpp
index edbba35d..b6c712c4 100644
--- a/windows/colorbutton.cpp
+++ b/windows/colorbutton.cpp
@@ -41,6 +41,7 @@ static BOOL onWM_COMMAND(uiControl *c, HWND hwnd, WORD code, LRESULT *lResult)
 		b->g = rgba.g;
 		b->b = rgba.b;
 		b->a = rgba.a;
+		invalidateRect(b->hwnd, NULL, TRUE);
 		(*(b->onChanged))(b, b->onChangedData);
 	}
 
diff --git a/windows/colordialog.cpp b/windows/colordialog.cpp
index 096135dc..0c17dd28 100644
--- a/windows/colordialog.cpp
+++ b/windows/colordialog.cpp
@@ -363,13 +363,22 @@ static LRESULT CALLBACK svChooserSubProc(HWND hwnd, UINT uMsg, WPARAM wParam, LP
 {
 	ID2D1RenderTarget *rt;
 	struct colorDialog *c;
+	D2D1_POINT_2F *pos;
+	D2D1_SIZE_F *size;
 
+	c = (struct colorDialog *) dwRefData;
 	switch (uMsg) {
 	case msgD2DScratchPaint:
 		rt = (ID2D1RenderTarget *) lParam;
-		c = (struct colorDialog *) dwRefData;
 		drawSVChooser(c, rt);
 		return 0;
+	case msgD2DScratchLButtonDown:
+		pos = (D2D1_POINT_2F *) wParam;
+		size = (D2D1_SIZE_F *) lParam;
+		c->s = pos->x / size->width;
+		c->v = 1 - (pos->y / size->height);
+		updateDialog(c, NULL);
+		return 0;
 	case WM_NCDESTROY:
 		if (RemoveWindowSubclass(hwnd, svChooserSubProc, uIdSubclass) == FALSE)
 			logLastError(L"error removing color dialog SV chooser subclass");
diff --git a/windows/d2dscratch.cpp b/windows/d2dscratch.cpp
index f9504317..146eea8b 100644
--- a/windows/d2dscratch.cpp
+++ b/windows/d2dscratch.cpp
@@ -6,6 +6,10 @@
 // - wParam - 0
 // - lParam - ID2D1RenderTarget *
 // - lResult - 0
+// You can optionally also handle msgD2DScratchLButtonDown, which is sent when the left mouse button is either pressed for the first time or held while the mouse is moving.
+// - wParam - position in DIPs, as D2D1_POINT_2F *
+// - lParam - size of render target in DIPs, as D2D1_SIZE_F *
+// - lResult - 0
 // Other messages can also be handled here.
 
 // TODO allow resize
@@ -37,6 +41,26 @@ static HRESULT d2dScratchDoPaint(HWND hwnd, ID2D1RenderTarget *rt)
 	return rt->EndDraw(NULL, NULL);
 }
 
+static void d2dScratchDoLButtonDown(HWND hwnd, ID2D1RenderTarget *rt, LPARAM lParam)
+{
+	double xpix, ypix;
+	FLOAT dpix, dpiy;
+	D2D1_POINT_2F pos;
+	D2D1_SIZE_F size;
+
+	xpix = (double) GET_X_LPARAM(lParam);
+	ypix = (double) GET_Y_LPARAM(lParam);
+	// these are in pixels; we need points
+	// TODO separate the function from areautil.cpp?
+	rt->GetDpi(&dpix, &dpiy);
+	pos.x = (xpix * 96) / dpix;
+	pos.y = (ypix * 96) / dpiy;
+
+	size = rt->GetSize();
+
+	SendMessageW(hwnd, msgD2DScratchLButtonDown, (WPARAM) (&pos), (LPARAM) (&size));
+}
+
 static LRESULT CALLBACK d2dScratchWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
 	LONG_PTR init;
@@ -83,6 +107,14 @@ static LRESULT CALLBACK d2dScratchWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, L
 	case WM_PRINTCLIENT:
 		// TODO
 		break;
+	case WM_LBUTTONDOWN:
+		d2dScratchDoLButtonDown(hwnd, rt, lParam);
+		return 0;
+	case WM_MOUSEMOVE:
+		// also send LButtonDowns when dragging
+		if ((wParam & MK_LBUTTON) != 0)
+			d2dScratchDoLButtonDown(hwnd, rt, lParam);
+		return 0;
 	}
 	return DefWindowProcW(hwnd, uMsg, wParam, lParam);
 }
diff --git a/windows/uipriv_windows.hpp b/windows/uipriv_windows.hpp
index d0b84a8c..d1380af3 100644
--- a/windows/uipriv_windows.hpp
+++ b/windows/uipriv_windows.hpp
@@ -13,8 +13,8 @@ enum {
 	msgNOTIFY,
 	msgHSCROLL,
 	msgQueued,
-	// TODO convert to a function like with container?
 	msgD2DScratchPaint,
+	msgD2DScratchLButtonDown,
 };
 
 // alloc.cpp