LaTeX Error: Option clash for package xcolor. Package xcolor Error: Undefined color `Lavender'. Why it is happening

I want to add a colour gradiant inner to outer from Lavender to white

usepackage{amsmath}
usepackage{times}
usepackage{anyfontsize}
usepackage{amsfonts}
usepackage[paperheight=11in,paperwidth=11in,margin=1in]{geometry}
usepackage{tikz}
usepackage[dvipsnames]{xcolor}
usepackage{tcolorbox}

usepackage{graphicx}
graphicspath{{images/}}

begin{document}
    
newtcolorbox{mybox}{colback=blue!5!white,colframe=blue}

%for gradiant background this code below


begin{tikzpicture}[remember picture,overlay]
path [inner color=Lavender,outer color=White] (current page.north east)rectangle (current page.south west);
end{tikzpicture}

begin{center}
thispagestyle{empty}

{fontsize{40}{20}selectfonttextbf{underline{Functional Equation Week: Problem 5}}}
        
vspace*{1cm}
        
{fontsize{35}{30}selectfonttextbf{Send me Your Answer!}}
vspace*{1cm}
end{center}
        
{fontsize{30}{30}selectfont Find all functions $ f : mathbb Rto mathbb R$ such that [ x^2y^2 left( f(x+y)-f(x)-f(y) right)=3(x+y)f(x)f(y)] holds for all reals $x$ and $y$}
        
vspace{1cm}
begin{center}  
{fontsize{30}{30}textbf{ONLY ELEMENTARY SOLUTIONS ALLOWED}}
        
vspace{1cm}

{fontsize{50}{60}selectfont $$boldsymbol{sum limits_{i=0}^{Creative} Math_i = Solving}$$}
        
vspace{1cm}
        
begin{mybox}Huge{begin{center}textbf{textcolor{blue}{Solution $to$}} end{center}}end{mybox}
end{center}
end{document}

But when i am compiling this it is showing me

! LaTeX Error: Option clash for package xcolor

! Package xcolor Error: Undefined color `Lavender’.

! Package xcolor Error: Undefined color `White’.

Why it is happening. Tell me the correct code