Blue and pink colours can no longer be used to imply that a toy is intended for boys or girls.
Spain's government has agreed on a new code of conduct that will prevent toy manufacturers from using sexist stereotypes in their adverts.
Companies will no longer be allowed to use blue or pink colours to imply that their products are intended for boys or girls.
The "self-regulatory code" will aim to "avoid prejudice and gender roles and the sexualised representation of little girls", the country's consumer affairs ministry said in a statement.
"It will ... avoid the exclusive association of toys that reproduce roles, such as those of care, domestic work and beauty for them, and action, physical activity and technology for boys," it added.
"The ads will also try to use inclusive language and present positive role models to encourage healthy, responsible and sustainable consumption."
The agreement was signed on Wednesday by the government, the Spanish Toy Manufacturers Association and Autocontrol, who regulate the country's advertising industry. It is expected to come into force on December 1, before the Christmas period.
In recent years, more toy companies and advertisers have been forced to withdraw ads over allegations of sexism.
In December, Spain's Minister for Consumer Affairs Alberto Garzon organised a symbolic toy "strike" to protest against gender stereotypes.
Several European countries have already taken similar initiatives, including the UK's Advertising Standards Authority.