Recently I was making a project on scratch and I was making the costume for the sprite. The sprite that I was making was white and the background for costume making is light gray and white, so it was hard to see the costume I was making, I could hardly see what I was doing to the costume.
I thought a color changing-button/setting would be nice so that the grid in the background would make it easier to see what I was erasing/adding to the costume. For example If I was making a white and some other color costume I could change the background to black and gray or just black or light gray and dark gray or just dark gray.
A setting/button would be nice because when people are making a sprite they can see what colors go well with the sprite colors or let the costume stand out more when they are making there costume for their costume. The setting/button could be like when you can choose the color for the shape/spot you are making.

well It is a nice idea, however there are a few issues:
1. There is an easy workaround. If you are working on something white, either colour it last or put a dark coloured rectangle behind it.
2. The actual stage is white so a white editor helps you picture what it will look like. If a white thing isn't visible enough in the editor, it likely won't be visible in the game.

Though i do support the idea of a “dark mode” stage setting where you can set the entire page to darker colours (useful at night)

When I use the eraser it will erase what ever is behind it.

h-o-u wrote:

When I use the eraser it will erase what ever is behind it.

what do you mean?
Wait do you use bitmap?

Because I was erasing parts of a picture and on vector you cant do that.

h-o-u wrote:

Because I was erasing parts of a picture and on vector you cant do that.

but when you turn a vector image to bitmap and then back to vector, you can't edit it. If you're using bitmap, the best thing you can do is make the stage dark and paint on the costumes editor but look at the stage.

how do you make the stage dark?

go to the backgrounds section and draw a big black rectangle to fill the entire stage