How do I color the page number in a partial TOC?

Question

I am writing a thesis and have the first two pages of each chapter colored gray with white text, before starting with the sections on white pages. I now want a partial TOC in each chapter, on these gray pages, and thus in white text. Although the section titles are now colored white, the page numbers are still black. How do I get the page numbers to be white as well in the partial TOC (while remaining black in the main TOC)?
Edit: The main TOC contains some lines of text to divide the contents into parts (this is just in the contents for clarity, the parts are not coded or numbered in any way). This seems not compatible with the solution provided.

MWE:

\documentclass{book}
\usepackage{titletoc,xcolor}
\usepackage[pagecolor=none]{pagecolor}

\begin{document}
\tableofcontents
\addtocontents{toc}{\setcounter{tocdepth}{0}}

\color{white}
\chapter{This is Chapter 1}
\thispagestyle{empty}\newpagecolor{gray}

\newpage\thispagestyle{empty}
\startcontents[section]
\printcontents[section]{}{1}{\addtocontents{ptc}{\setcounter{tocdepth}{2}}}

\newpage\newpagecolor{white}
\color{black}
\section{bla}\section{bla}

\addtocontents{toc}{\smallskip \textit{Modeling} \medskip \par}

\chapter{This is Chapter 2}%would be made up like Chapter1; omitted here for clarity
\chapter{This is Chapter 3}

\addtocontents{toc}{\smallskip \textit{Experiments} \medskip \par}

\chapter{This is Chapter 4}
\chapter{This is Chapter 5}

\end{document}

Answer 1

The trick used here is that I define my page-numbers colour as a variable. Like this, I am able to switch it wherever I want. I define it as black by default. In front of the partial TOC, I do a \colorlet{MyColor}{white} which switches to your desired colour (here white) and after the partial TOC, I switch it back to black. The last switch is not needed in this example, but just to be sure...

If you like, you may colour each chapter differently like this.

% arara: pdflatex
% arara: pdflatex

\documentclass{book}
\usepackage{titletoc,xcolor}
\usepackage[pagecolor=none]{pagecolor}
\definecolor{MyColor}{named}{black}

\makeatletter
\let\oldl@chapter\l@chapter
\def\l@chapter#1#2{\oldl@chapter{#1}{\textcolor{MyColor}{#2}}}

\let\old@dottedcontentsline\@dottedtocline
\def\@dottedtocline#1#2#3#4#5{%
\old@dottedcontentsline{#1}{#2}{#3}{#4}{{\textcolor{MyColor}{#5}}}}
\makeatother

\begin{document}
\tableofcontents
\addtocontents{toc}{\setcounter{tocdepth}{0}}

\color{white}
\chapter{This is Chapter 1}
\thispagestyle{empty}\newpagecolor{gray}
\newpage\thispagestyle{empty}
\colorlet{MyColor}{white}
\startcontents[section]
\printcontents[section]{}{1}{\addtocontents{ptc}{\setcounter{tocdepth}{2}}}
\colorlet{MyColor}{black}

\newpage\newpagecolor{white}
\color{black}
\section{bla}
\section{bla}
\end{document}