pyqtgraph scatter plot in PySide2 swaps red and blue - pyside2

Question

I'm using a PNG image as a background to a scatter plot, but the import somehow swaps red and blue. I can 'fix' it by swapping red and blue for each pixel, but that's not a proper solution. Does anyone know what goes wrong here?
See code below:
import sys
from PySide2.QtWidgets import (
QApplication, QMainWindow, QWidget, QVBoxLayout,
)
from PySide2.QtGui import (
QImage
)
import pyqtgraph as pg
class Window(QMainWindow):
def __init__(self):
super().__init__()
self.setWindowTitle("RGB Issue")
self.setGeometry(100, 100, 600, 200)
# set up widgets
self.add_widgets()
# show widgets
self.show()
def add_widgets(self):
# create a plot window
plot = pg.plot()
# add an image
img = QImage('flowers.png')
# convert to a format imageToArray accepts
img = img.convertToFormat(QImage.Format_ARGB32_Premultiplied)
img_array = pg.imageToArray(img, copy=True)
# ==> uncomment next line to swap red and blue
# img_array = self.swap_red_and_blue(img_array)
img_item = pg.ImageItem(img_array)
# push image back so it ends up behind the spots in the plot
img_item.setZValue(-100)
plot.addItem(img_item)
# create a layout for our widget
layout = QVBoxLayout()
# our central widget
widget = QWidget()
# set widget layout
widget.setLayout(layout)
layout.addWidget(plot)
self.setCentralWidget(widget)
def swap_red_and_blue(self, img_array):
# swap red and blue for each pixel
for r in img_array:
for c in r:
c0old = c[0] # get red value
c1old = c[1] # get green value
c2old = c[2] # get blue value
c[0] = c2old # replace red with blue
c[1] = c1old # keep green
c[2] = c0old # replace blue with red
# c[3] = 255 # set alpha to opaque
return img_array
if __name__ == '__main__':
app = QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec_())
This is the original image:
This is the output I get:
I get the correct output if I call method swap_red_and_blue for each pixel in the code above.