How to set the color of caret blinking cursor in QLineEdit

There is one way you can give a try. Theoretically it looks like it should work (not tested. Look for compile time errors.)

First get the image of icon you want to set. Then load the image to get QPixmap object.

QPixmap myPixmap;
myPixmap.load("<<YOURIMAGEPATH>>/cursoricon.png");

Now set the color to QPixmap using https://doc.qt.io/qt-5/qpixmap.html#fill

myPixmap.fill(QColor(0,255,0));

Now create a QCursor object using QPixmap object https://doc.qt.io/qt-5/qcursor.html#QCursor-3

QCursor cursor = QCursor(myPixmap);

Then set the cursor to your line edit object.

pLineEdit->setCursor(cursor);

Actually the setCursor function, first I thought it works only for mouse cursor. But the documentation says it holds good for editor widgets also. https://doc.qt.io/qt-5/qwidget.html#cursor-prop

An editor widget might use an I-beam cursor