Would u plz help me find the meaning of two quotation of Macbeth?

Question

LADY MACBETH:
Infirm of purpose!
Give me the daggers: the sleeping and the dead
Are but as pictures:" 'tis the eye of childhood
That fears a painted devil." If he do bleed,
I'll gild the faces of the grooms withal;
For it must seem their guilt.


Re-enter LADY MACBETH
LADY MACBETH:
My hands are of your colour; but I shame
To wear a heart so white.
I hear a knocking
At the south entry: retire we to our chamber;
A little water clears us of this deed:
How easy is it, then! "Your constancy
Hath left you unattended."

1-Does "painted devil" means imaginary devil?
2-As I underestand " Your constancy
Hath left you unattended"one means: your firmness has gone. but somewhere I read it means your lack of firmness has gone. which one is correct?
Tanx

Answer 1

1. Yes

2 You're right in your reading of that line.
"Your lack of firmness has gone," would mean that you are now resolved and determined. This line actually means you're wavering and not resolved. You are not firm in intent.

Answer 2

I think that "painted devil" means a picture - an image of a devil, not a real one.