Qt QMessageBox show buttons without color

I've created an QMessageBox with customized buttons and they are showing up in gray as the image bellow:

Running on Linux is fine! But on Raspberry it gives me in trouble. The snippet of code that I wrote is the following:

#include "alertmessage.h"
#include <QDebug>
#include <QAbstractButton>
#include <QCoreApplication>
AlertMessage::AlertMessage(QMessageBox *parent): QMessageBox(parent)
{

    this->setFont(QFont("Roboto"));
    QFont font = this->font();
    font.setPointSize(26);
    this->setMaximumHeight(250);
    this->setModal(true);
    this->setMaximumWidth(this->minimumHeight());
    this->setWindowTitle(QString("Falha de conexão"));
    this->setChecker(new QCheckBox("Não mostrar essa menssagem novamente.", this));
    this->setText(QString("<p style='margin-bottom: 0cm; line-height: 100%; text-align: justify;'>"
"Houve uma falha de comunica&ccedil;&atilde;o com um ou mais sensores, isso poder&aacute; "
"afetar o desempenho do sistema.</p>"));
    this->setInformativeText(QString("<p style='margin-bottom: 0cm; line-height: 100%; text-align:justify;'><strong>Voc&ecirc;"
" quer continuar ou <span style='color: #ff0000;'>PARAR</span> a aplica&ccedil;&atilde;o?</strong></p>"));
    this->setStandardButtons(QMessageBox::No | QMessageBox::Yes);
    this->setButtonText(QMessageBox::No, QString("Parar").toUpper());
    this->setButtonText(QMessageBox::Yes, QString("Continuar"));
    QPalette okPalette = this->button(QMessageBox::Yes)->palette();
    QPalette noPalette = this->button(QMessageBox::No)->palette();
    okPalette.setColor(QPalette::Button, QColor(13, 71, 161));
    okPalette.setColor(QPalette::ButtonText, QColor(Qt::white));
    noPalette.setColor(QPalette::Button, QColor(127, 0, 0));
    noPalette.setColor(QPalette::ButtonText, QColor(Qt::white));
    this->button(QMessageBox::Yes)->setPalette(okPalette);
    this->button(QMessageBox::No)->setPalette(noPalette);
    this->setIcon(QMessageBox::Warning);
    this->setCheckBox(this->getChecker());
    this->connect(this->button(QMessageBox::Yes), SIGNAL(clicked()), this, SLOT(turnVisible()));
    this->connect(this->button(QMessageBox::No), SIGNAL(clicked()), this, SLOT(turnOFF()));


}

I solved it, each OS has some default styles and Qt will search for they to look more "native". Taking that into account I need to force my application to take a Style different from the raspberry standards styles. The snipe of code that solved that:

QApplication  app(argc, argv);
qDebug() << QStyleFactory::keys(); //See available styles
app.setStyle("Fusion");