[FEAT] Add colorblind mode

[pedrohenricaval]

I suggest adding a colorblind mode to the snake game, providing alternative color schemes designed for players with different types of color vision deficiency.

In this mode, elements would be distinguished not only by color but also by strong contrast, patterns, or clearly different shades.

Adding this feature would improve the game’s accessibility, allowing more players to enjoy it.

[JavadTe]

Hi, I am a beginner contributor, and I am working on this project for an open-source contribution assessment. I would like to investigate this accessibility feature and try to add a simple colourblind-friendly visual option.

I will keep the change small, follow the contributing guide, and test it locally before opening a pull request.

Thank you.