Dreams involving deceased loved ones, such as your grandmother, often carry significant emotional weight and can symbolize guidance, love, and comfort. Your grandmother advising you not to be late may indicate that she is encouraging you to be mindful of time in your life, possibly related to personal goals or relationships. The storm outside could represent turmoil or challenges you are currently facing, suggesting that you may need to navigate through difficult emotions or situations.

The different colored birds walking like humans could symbolize freedom, transformation, or the diversity of experiences in your life. Birds often represent thoughts or messages from the spiritual realm, and their unusual behavior in your dream might suggest that you're being called to see things from a new perspective or embrace change.

Overall, this dream may be urging you to stay grounded and aware of your life's direction while also reminding you that support and guidance are available to you, even in challenging times. Consider reflecting on any current situations where you might be feeling overwhelmed and how your grandmother's wisdom could apply to your life.