OpenCV can not detect specific color well - c++

Question

this is the one not applying the mask
this is the one applying the mask
Even though it detects vaguely, I want to make it more clear.
void MainWindow::updatePicture(){
Mat frame;
Mat blurred;
Mat grayBlurred;
Mat hsvBlurred;
Mat diff;
Mat movingObjectMask;
Mat colorMask;
Mat result;
this->cap.read(frame);
blur(frame, blurred, Size(this->kernel, this->kernel)); // blur the frame
cvtColor(blurred, grayBlurred, COLOR_BGR2GRAY); // convert to gray
/* make a mask that finds a moving object */
absdiff(this->previous, grayBlurred, diff); // compare it with previous frame which was blurred and converted to gray
threshold(diff, movingObjectMask, this->thresholdVal, 255, THRESH_BINARY); // binarize it
cvtColor(movingObjectMask, movingObjectMask, COLOR_GRAY2BGR);
/* make a mask that finds a specific color */
cvtColor(blurred, hsvBlurred, COLOR_BGR2HSV); // convert to HSV to track a color
inRange(hsvBlurred, this->hsvLowerBound, this->hsvUpperBound, colorMask); // track the color
cvtColor(colorMask, colorMask, COLOR_GRAY2BGR);
/* apply the masks */
bitwise_and(frame, movingObjectMask, result);
bitwise_and(result, colorMask, result);
cvtColor(result, result, COLOR_BGR2RGB);
/* end */
this->myLabel->setPixmap(mat2QPixmap(result, QImage::Format_RGB888));
this->previous = grayBlurred;
}
As you can see in the code, I make two masks that detect a moving object and a specific color(technically colors in a specific range).
Upper and lower hsv range were calculated like below.
void MainWindow::refreshRgb(){
Scalar lowerBound = hsvMult(this->currentHsv, 1 - this->ratio);
Scalar upperBound = hsvMult(this->currentHsv, 1 + this->ratio);
this->hsvLowerBound = lowerBound;
this->hsvUpperBound = upperBound;
}
Scalar hsvMult(const Scalar& scalar, double ratio){
int s = static_cast<int>(scalar[1]*ratio);
int v = static_cast<int>(scalar[2]*ratio);
if(s > 255)
s = 255;
if(v > 255)
v = 255;
return Scalar(static_cast<int>(scalar[0]), s, v);
}
How can I make it more clear?