I want to set the background color as the color picked from my CMFCColorButton - c++

Question

I have the color picked from my CMFCColorButton and now I want to set it to the background (if it's not already the current color).
I can't seem to figure out how, so I would really appreciate your help and explanation.
void CMainFrame::OnColor()
{
// m_TextColors is the ID of the color button I created in the resource editor.
CMFCRibbonColorButton* pColorBtn = DYNAMIC_DOWNCAST(CMFCRibbonColorButton, m_wndRibbonBar.FindByID(m_TextColors));
COLORREF color = pColorBtn->GetColor();
CWnd* pwndParent = this->GetParent();
CRect rcClient;
pwndParent->GetClientRect(&rcClient);
if (color != GetSysColor(COLOR_BACKGROUND)) {
CBrush brush;
CClientDC dc(this);
brush.CreateSolidBrush(color);
dc.FillRect(rcClient, &brush);
}
else {
MessageBox(_T("Same Color."), MB_OK);
}
}
I made some changes:
void CMainFrame::OnColor()
{
// m_TextColors is the ID of the color button I created in the resource editor.
CMFCRibbonColorButton* pColorBtn = DYNAMIC_DOWNCAST(CMFCRibbonColorButton, m_wndRibbonBar.FindByID(m_TextColors));
COLORREF color = pColorBtn->GetColor();
CBrush brush;
brush.CreateSolidBrush(color);
CRect rc;
GetClientRect(&rc);
GetWindowRect(&rc);
CClientDC dc(this);
dc.SelectObject(&rc);
if (color != GetSysColor(COLOR_WINDOW)) {
dc.FillRect(rc, &brush);
} else {
MessageBox(_T("Same Color."), MB_OK);
}
}
And this is the result:
It's tracing the document's color but not changing it, it's changing the whole window's color.
Update: I've tried the invalidateRect function, this is the result:
It seems like it's adding color on top of my MDI client area not in it in the background like i intended,

Answer 1

Have you tried:
void CMainFrame::OnButColor()
{
HBRUSH hBrush=CreateSolidBrush(RGB(0,0,255));
SetClassLong(m_hWndMDIClient, BGCL_HBRBACKGROUND,(LONG)hBrush);
::InvalidateRect(m_hWndMDIClient,0,TRUE);
}