QColorButton is a widget to show an initial color and choose a different color when it's double-clicked.
There's an api to set the initial color for QColorButton and retrieve its new color.
Copy QColorButton.ui, QColorButton.h, QColorButton.cpp, QColorSwatch.h, QColorSwatch.cpp to your project. Make sure your build system does auotmatic creation of moc files from the .ui file.
Running the test program will initially show a window with an initial color. Red in the case of the test program.
Double click the red area to bring up the standard color dialog.
Selecting OK after choosing a different color will result in the red area changing to the color you chose.
Download the latest code using 'clone'.
% git clone https://github.com/epasveer/QColorButton
Setup cmake and build
% cd QColorButton/src
% cd build
% cmake ..
% make
Install it (or not), which will usually copy it to /usr/local/bin. May need root access.
% cd QColorButton/src/build
% sudo make install
QColorButton source code is licensed under the MIT License.