"Proof that simple packs do not reduce lag"
It is a common misconception amongst new texturers that simple packs reduce lag. Many arguments have been made against it, and I am here with my two cents. So, here is complete, legitimate proof that simple packs do not reduce lag.

Image with the default Minecraft (High color texture pack): 11fps



Image with Thorns (Low color texture pack): 10fps



Image with the Xaiwaker (Simple pack): 11fps



So, why do simple packs not reduce lag? Well, it is quite simple. People would like to think that Minecraft renders the textures based on colors, meaning that if it has less colors, it has less to render. Unfortunately, this is not how it works. Instead, minecraft renders the individual pixels on the textures, meaning that at a 16x resolution, no matter how simple the pack is, it still has 256 pixels to render per texture. This is why some biomes are more laggy than others, they have more blocks to load, and therefore, more texture to render.

So, how can a texture pack affect fps? Well, the only way to do that is to reduce the amount it has to render, meaning changing the resolution. So, that is why you get more lag with high resolution packs, like 32x, or 64x, then you do with 8x, 4x, etc..

Thank you for reading.
-Peyton A., Texture Artists' Union Administrator.