Fixes #1527 as discussed there.
In `win32_show_color_dialog`, `utils_scale_round` is not necessary at all because [`Get{R,G,B}Value`](https://msdn.microsoft.com/en-us/library/windows/desktop/dd144923.aspx) already return 0..255, which we can immediately render as hex.
The resulting code behaves correctly for me under all configurations: Linux and Windows, GTK+2 and GTK+3, with or without native Windows dialogs. (The native [Windows color dialog](https://i-msdn.sec.s-msft.com/dynimg/IC534143.png) does not show `#RRGGBB`, but it does show the individual R, G, B bytes, and I checked against those.)
However, I still have no idea why @elextr was unable to reproduce #1527 while I can easily reproduce it in all configurations (with GTK+ color picker).
I’m also not sure why I remember not having this issue in the past, but it’s likely that I only used the color chooser a few times back then, so I may have missed it. You can view, comment on, or merge this pull request online at:
https://github.com/geany/geany/pull/1536
-- Commit Summary --
* Fix converting color to hex for insertion
-- File Changes --
M src/utils.c (14) M src/win32.c (5)
-- Patch Links --
https://github.com/geany/geany/pull/1536.patch https://github.com/geany/geany/pull/1536.diff