First press escape then the following:
lowercase		uppercase
r	red text	red graphics	R
g	green text	green graphics	G
y	yellow text	yellow graphics	Y
b	blue text	blue graphics	B
m	magenta text	magenta graphics	M
c	cyan text	cyan graphics	C
w	white text	white graphics	W
d	normal height	double height	D
f	steady	flash	F
h	release graphics	hold graphics	H
i	insert row	delete row	I
n	black background	new background	N
q	hide codes	show codes	Q
s	contiguous graphics	separated graphics	S
v	reveal off	reveal on	V
x	no grid	grid	X
z	redraw screen	clear screen	Z
[	narrower screen	wider screen	]
O	conceal	insert block char.	J
U	duplicate row	switch char. sets	1-8
0	hide status bar
E	export frame	toggle metadata	L
a	ignore black fg	allow black fg	A
k	black text	black graphics	K
No escape required for:
TAB	insert space	delete character	BS
In graphics mode:
QWASZXRCF/keypad		subpixel twiddling
Bug reports and pull requests welcome.
The frame's data is all in the address bar. To save or share, bookmark/email/etc the URL.