You can use this code to Custom CSS to change color of Blog Title, Excerpt, Date, Author.
/* Title */
div[class*="card-content__CardContentTitle"] {
color: #f1f;
}
/* Excerpt */
div[class*="card-content__CardContentTitle"]+div {
color: brown;
}
/* Date Author */
div[class*="card-content__CardContentTitle"]+div+div {
color: gold;
}
Result