Can I please request you to translate your question into English? There are not many people here who will understand Spanish, and hence translating will really improve your chances of getting help?
Based on what I understood from Google translate, I think you're misunderstanding. The colours are not random. You've supplied iris$Species as colour, and R detects that it is a factor variable with 3 levels. So, after plotting the points, it colours them with the 1st 3 colours in the current colour palette, which are "black", "red" and "green3" unless you change it.
If you want to change the colours as you wish, you can take a look at palette function. You can specify a vector of colours and that will become the palette. For any plot, it'll start from the first colour of the palette, and continue. If the palette ends, it'll start back at the first colour.
Hi Cesar,
As Yarnabrina said, English is the preferred language here, If you have problems with English and need help in Spanish, feel free to contact me via DM. I hope you don't minde I that had translated your post
Hola cesar
Como dijo Yarnabrina, el inglés es el idioma preferido aquí. Si tiene problemas con el inglés y necesita ayuda en español, no dudes en comunicarte conmigo a través de un mensaje directo. Espero que no te importe que haya traducido tu publicación.