[Fizzlemizz]

I mouseover, OK put the white color. I mouseleave, OK Red again. I click, OK turns white. I mouseleave (when the panel be clicked) and OK, continue white. But, when I mouseleave one more time the panel turn Red again.

OnLeave

if not self.clicked then
    local _, Class = UnitClass("player")
    local Color = RAID_CLASS_COLORS[Class]
    self.text:SetTextColor(Color.r,Color.g,Color.b)
else
    self.clicked = false
end

Because you "self.clicked = false" on the first OnLeave the condition "if not self.clicked then" becomes active on the second OnLeave. You need to find some mechanism (maybe a second click) to reset "self.clicked", in which case,

OnClick becomes:

if not self.clicked then
	self.clicked = true
	
	ChatFrame3:Show()
	ChatFrame1:Hide()
	ChatFrame2:Hide()
	
	self.text:SetTextColor(1, 1, 1)
	
	local tab1 = kgPanels:FetchFrame("PanelGene")
	local tab2 = kgPanels:FetchFrame("PanelLog")
	
	local _, Class = UnitClass("player")
	local Color = RAID_CLASS_COLORS[Class]
	tab1.text:SetTextColor(Color.r,Color.g,Color.b)
	tab2.text:SetTextColor(Color.r,Color.g,Color.b)
else
	self.clicked = false
ens

And OnLeave becomes:

if not self.clicked then
	local _, Class = UnitClass("player")
	local Color = RAID_CLASS_COLORS[Class]
	self.text:SetTextColor(Color.r,Color.g,Color.b)
end