For the vibration which he sends out tends to arouse a new and higher part of their mental bodies, and consequently to open before them altogether new fields of thought.
It may not be exactly the same thought as that sent out, but it is of the same nature.

The undulations generated by a man thinking of Theosophy do not necessarily communicate Theosophical ideas to all those around him; but they do awaken in them more liberal and higher thought than that to which they have before been accustomed.

On the other hand, the thought-forms generated under such circumstances, though more limited in their action than the radiation, are also more precise; they can affect only those who are to some extent open to them, but to them they will convey definite Theosophical ideas.
The colours of the astral body bear the same meaning as those of the higher vehicles, but are several octaves of colours below them, and much more nearly approaching to such hues as we see in the physical world.

It is the vehicle of passion and emotion, and consequently it may exhibit additional colours, expressing man's less desirable feelings, which cannot show themselves at higher levels; for example, a lurid brownish-red indicates the presence of sensuality, while black clouds show malice and hatred.

A curious livid grey betokens the presence of fear, and a much darker grey, usually arranged in heavy rings around the ovoid, indicates a condition of depression.