QCustomPlot Discussion and Comments

I want to add three y axis. But these are should have different color. It is possible?

// Creating a color to use while drawing the axis
QColor axis_color(255, 0, 0); // QColor(RED, GREEN, BLUE, ALPHA);
// Creating a pen to use for drawing the axis
QPen axis_pen;
// Assigning the desired color to the pen
axis_pen.setColor(axis_color);
// Assigning the previously created pen to the axis you want to draw
MyGraph->MyAxis->setBasePen(axis_pen);

For further reference please have a look at the QCPAxis documentation:
http://www.qcustomplot.com/documentation/classQCPAxis.html

I changed axis color by using your code. How can I change color of numbers of y axis?

graph->xAxis->setTickLabelColor(QColor(0, 0, 0));

Don't get me wrong but you should really have a look at the documentation...