Change the colours in the colour styles (Page, Ink, Accent, and Deep light, Deep and Deep shadow, which the panel gradient runs across). Everything, including the code components, reads them.
Page
#E9E8E4
Surface
#F3F2EF
Ink
#18181A
Body
#4A4A4E
Muted
#86868A
Line
#D3D2CD
Deep light
#3F8487
Deep
#2A6168
Deep shadow
#1B4049
Deep raised
#33707A
Deep line
#52808A
On deep
#F2F7F5
On deep body
#C9DCDA
On deep muted
#9DBBBC
Accent
#8FD1C2
Accent deep
#3D7A6D
Each changes the three Deep styles; the panels follow.
Dusk
Deep light #7479CB
Deep #565CB1
Deep shadow #3D4391
Plum
Deep light #8A6198
Deep #644478
Deep shadow #432C57
Black
Deep light #262626
Deep #141414
Deep shadow #0C0C0C
Display · h1 (hero and page titles)
Closing · h2
Statement · h2 (section heads)
Title · h3
Prose heading · h2 in articles
Lead
Body
Small
Nav
Button
Big figure
Figure
Read the Plans, Areas and Questions collections through hidden Feed lists next to them. The plan picker shows each room as a photo: set one photo per kind of room in its controls.
Sun room and Sun heading (code)
The Closing. As it scrolls in, the sun swings up from the floor and lights the heading word by word. Type the two lines in Sun heading; on Sun room, put Sun from on the window of your photo.
