Hi, The multicolored mucus especially yellow indicates that your bodys defense has taken well care about the infection. You need not worry as I find no fever in your history. I presume you are violently clearing your nose and throat secretions which might have injured some mucosa resulting in a twinge of mixed blood which is self limiting. However, if the bleeding persists, you need to seek a personal medical attention. Steam Inhalation is the best home remedy and the viral infection shall subside on its own. Hope this helps.