Why is Ralph blushing when the author writes Ralph spoke first crimson in the face?

To quote from chapter 2: Fire on the Mountain... 'Ralph spoke first, crimson in the face.' The reason why Ralph blushed was because he'd just realised that, after spending a great deal of effort organising the building of a huge fire, he had no means to light the fire. Ralph blushed from a combination of embarrassment and from the shame of having to publicly admit that he didn't have any way of lighting the fire.