My first cryptogram

Logic Level 1

\[\large{\begin{array} && \color{blue}A & \color{red}B & \color{purple}C \\ & \color{blue}A & \color{red}B & \color{purple}C \\ + & \color{blue}A & \color{red}B & \color{purple}C \\ \hline &\color{purple}C & \color{purple}C & \color{purple}C \end{array}}\]

\[\large \overline{\color{blue}A\color{red}B \color{purple}C} = \ ?\]