Created attachment 108977 [details]
Example Image

Description of problem:
In Kolourpaint 17, if you select the colour black and draw a 1px line, it is grey (#7F7F7F) instead of black (#000000). Also if you draw lines in other colours, they are slightly different. And thicker lines are not fully in the colour you selected. If you, e. g. draw a black line, and zoom in, you see:
- the 2 pixel line starts and ends with a 2x1 pixel in grey
- the 4 and 6 pixel line has a grey border
- the 8 has some grey pixels at the beginning and end of the line.
I attached an example image.



Version-Release number of selected component (if applicable):
Fedora 27: kolourpaint-17.08.1-1.fc27.x86_64



How reproducible:
Always.



Steps to Reproduce:
1. Open Kolourpaint
2. Select colour "black" (#000000) as foreground colour
3. Select the "line" tool
4. Select the thinnest line type (1px)
4. Draw a line



Actual results:
The line is grey (#7F7F7F) instead of black.
(You can see this e. g. if you zoom in or use the colour pipette)



Expected results:
The line should be black.



Additional info:
* Workaround: If I downgrade to the RPM shipped in Fedora 26 (kolourpaint-16.12.3-1.fc26.x86_64.rpm, kolourpaint-libs-16.12.3-1.fc26.x86_64.rpm), everything works like expected. 

* Downstream BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1513540