I might do my own take on this.

These have way too much colors for SMB1.

here's a mockup i made in mspaint in the middle of online class of how this could look like with restrictions applied, the nes can do better than this but this is for SMB1 style specifically which doesn't have tile layers or multiple palletes on one tile so just 3 colors per tile, and only 3 palletes are used here

[EDIT] It won't let me embed the image for some reason, i uploaded it to google drive and grabbed the image url and i can view it in icognito mode so it's not that you can't get to the image without being logged in... am i messing up with the embed somehow? i was using [img]https://domain/subdomain[/img] format which should work according to the code reference.

here is the image link btw: https://lh3.googleusercontent.com/QgLkB_spFweIiDHOS4SYoN-h3JZrvOL84Kva7MgHoG-YYhHUOQW2lQLxZ9W_PzDgAaZHqIsCsPq_bqq129Q=w929-h590

@Doc
Yes and no, they do have a sort of transparency, but not like how it's shown in the image here.

@SMM123 Pretty sure they do, given how different background colors can be assigned to the same tile palette. Am I wrong regarding that?

These tiles are all too colorful, and NES tiles doesn't support transparent backgrounds.

Ah, I understand. Sorry if I misunderstood.

Here's an example I banged out of following restrictions. Now, it's sprites and not tiles, but the same principles apply.

That grass tile in the upper-left alone has 7 colours on it, and assuming you're not using black as a transparency that means that it would require three layers.

If you're emulating a style, ya gotta stay within its restrictions.

@RealDev You can't use all the colors at once, dude. There's four palette slots available for background tiles on the NES, each can have four different colors at a time. Four colors per tile, including one being transparent.

"Way too much colour for NES"

Bruh, look at the original sheet from SMB for object pallete. .-.

I literally used the pallete from the original game to make these.

I Think It's 16-Bit

Sorry, but these are nowhere near SMB1 NES (except maybe the sunflower and stalk). The game doesn't use shading or outlines, and these look Master System/Game Gear quality.

The Super Mario World pirate has tiles with four colours, but the corners had to be solid instead of transparent.

@Evan.F
Or do the layer thing like Mega Man sprites

Way too much colour for NES. I recommend limiting it to 4 colours (3 + a transparency colour)

@Mike If the Minus World is anything to go by, they do have transparency. They don't on Game Boy/Color, though, mighta gotten confused with that.

Looks great, but it doesn't fit the NES style whatsoever. There are too many colors, and I'm pretty sure tiles don't have transparency.