Well, this is a typical textbook question - "what do you think? (when there is no direct answer)".
When using this in class I've waiting for kids to come up with suggestions and a few have been "Well, it's like when you see a rainbow - the rain is just stopping and the sun is showing through - Elizabeth is telling us she is the sun shining through the bad times that have come before".
I'm not so sure about this one, but this does fit with the idea
of new hope, new dawn etc.
On the internet it says:
http://www.gospelcom...ce/words154.htm"No matter how bleak it looks, if God is with you, there's always a rainbow on the other side."
(entitled 'Why its a load
of old cobblers')
http://www.abarnett....rk.html#RAINBOW"According to the Bible, God placed a rainbow in the sky after the flood, presumably to brighten the place up a bit, what with all the mud and dead animals etc."
Rainbows and promises
http://www.childrens...rmons/noah3.htm"God’s sign that he would remember his promise was the rainbow. Have you ever seen a rainbow? Did you ever wonder what a rainbow was made
of? It is made
of light. In fact, it is made
of seven colors
of light. It only occurs when it rains. The light
of the sun shines through the rain, causing the light to bend (or refract) and reflect
off the rain. The rain acts like a prism, splitting the white light into the colors
of red, orange, yellow, green, blue, indigo (deep blue), and violet (purple). They always stay in the same order, because the frequency is from low to high. It always forms an arch. Does this sound like something God made? Yes, it is very orderly and dependable, just like God. Jesus is like the rainbow to us: when God sees us and our sin, he sees us through Jesus, who said "I am the light
of the world." God doesn’t see our sin due to the sacrifice Jesus made for us on the cross."
So, I think you're on the right track!
...and here's a good bit:
http://www.scribbles...generic158.html"The Rainbow Portrait is one
of the large paintings
of Elizabeth. It was painted when she was 67. You will notice that she doesn’t look 67, because the painter followed a “face pattern” created when she was much younger.
The gold writing is in Latin and says: “There is no rainbow without the sun”. This is meant to suggest that the queen is as important to the happiness of the people as the sun is to the rainbow. Putting writing in paintings was popular at the time. It is called an “impresa”. "
...but (

)
http://www.cofc.edu/...iconography.htm- “Rainbow” portrait painted for Robert Cecil by Gheeraerts c. 1600, employs “mask
of youth”; dominant image is rainbow (symbol
of peace); cloak has “eyes and ears” to represent loyal ministers; sleeve has serpent with heart pendant in mouth (showed wisdom to do right thing)
I think you should go with the inscription explanation - "No rainbow without a sun."
OK - fair enough?