pstats: Fix compile error on Windows with `STDFLOAT_DOUBLE=1`

Fixes #1408

pandatool/src/win-stats/winStatsMonitor.cxx

@@ -347,7 +347,9 @@ choose_collector_color(int collector_index) {
     sizeof(CHOOSECOLORA),
     _window,
     0,
-    RGB(encode_sRGB_uchar(current[0]), encode_sRGB_uchar(current[1]), encode_sRGB_uchar(current[2])),
+    RGB(encode_sRGB_uchar((float)current[0]),
+        encode_sRGB_uchar((float)current[1]),
+        encode_sRGB_uchar((float)current[2])),
     (LPDWORD)custom_colors,
     CC_FULLOPEN | CC_RGBINIT,
     0,