Is it allowed to use techniques similar to dithering but instead of pixel by pixel dithering, the use of sequential lines spaced one pixel apart to give the illusion of a lighter color?

Also, is the use of pixel noise using only the two colors allowed?

Well, "the use of sequential lines spaced one pixel apart to give the illusion of a lighter color" is allowed but using pixel noise is not; because pixel noise doesn't fit the theme even if it's only a few colors.

Hope this helps. By the way this is the first game jam I've hosted so if I host it again i'll be sure to include clearer guidelines.

Thanks!