This the code I use (I got it from here Link, and modified some lines to get black cards (oled).
BlueBlack:
# MyVariables
base-hue: '220' #Controls the base (and accent) color hue (0-360) | 0=Red 60=Yellow 120=Green 180=Cyan 240=Blue 300=Magenta 360=Red
base-sat: '5%' #Controls the saturation of the theme (0%-100%) | 0%=Grey 100%=Full Saturation
# MyVar
huesat: 'var(--base-hue), var(--base-sat),'
# Primary Color
primary-color: '#2581ab' #hsl(var(--huesat) 50%)' #header colors and some text colors
dark-primary-color: 'hsl(var(--huesat) 60%)'
light-primary-color: 'hsl(var(--huesat) 30%)'
accent-color: 'hsl(var(--huesat) 30%)'
# Backgrounds
primary-background-color: 'hsl(var(--huesat) 16%)'
secondary-background-color: 'hsl(var(--huesat) 16%)' # background behind cards
paper-listbox-background-color: "#000000" #'hsl(var(--huesat) 16%)'
paper-card-background-color: "#000000" # 'hsl(var(--huesat) 12%)'
paper-dialog-background-color: "#000000" #'var(--paper-card-background-color)'
table-row-background-color: "#000000" #'hsl(var(--huesat) 12%)'
table-row-alternative-background-color: "#000000" #'hsl(var(--huesat) 10%)'
# Divider
divider-color: 'hsla(0, 0%, 0%, 0)'
dark-divider-opacity: '0'
light-divider-opacity: '0'
dark-secondary-opacity: '1'
# Text colors
primary-text-color: 'hsl(var(--huesat) 90%)'
text-primary-color: 'hsl(var(--huesat) 90%)'
secondary-text-color: 'hsl(var(--huesat) 80%)'
disabled-text-color: 'hsl(var(--huesat) 70%)'
sidebar-text_-_color: 'hsl(var(--huesat) 90%)'
sidebar-text-color: 'hsl(var(--huesat) 90%)'
paper-card-header-color: 'hsl(var(--huesat) 90%)'
paper-button-ink-color: 'hsl(var(--huesat) 50%)'
# Text Adjustments
paper-font-headline_-_letter-spacing: '-0.5px'
paper-font-headline_-_font-weight: '400'
paper-font-body1_-_font-weight: '300'
# Nav Menu
paper-listbox-color: 'hsl(var(--huesat) 50%)'
paper-grey-50: 'hsl(var(--huesat) 50%)'
paper-grey-200: 'hsl(var(--huesat) 10%)' #active menu item
sidebar-icon-color: 'hsl(var(--huesat) 50%)' #iron-icon-fill-color
# Paper card
paper-item-icon-color: 'hsl(var(--huesat) 40%)'
paper-item-icon-active-color: 'var(--paper-item-icon-color)'
paper-item-icon_-_color: 'var(--paper-item-icon-color)'
paper-item-selected_-_background-color: 'hsla(0, 0%, 0%, 0.2)'
paper-item-selected_-_color: 'hsl(var(--huesat) 20%)' #?
paper-tabs-selection-bar-color: 'hsla(0, 0%, 0%, 0.2)'
paper-tab-ink: 'hsl(var(--huesat) 70%)'
paper-input-container-color: 'hsl(var(--huesat) 60%)'
# Labels
label-badge-red: 'var(--paper-card-background-color)'
label-badge-border-color: 'var(--label-badge-red)'
label-badge-background-color: 'var(--paper-card-background-color)'
label-badge-text-color: 'var(--primary-text-color)'
# Shadows
shadow-elevation-2dp_-_box-shadow: '0px 0px 0px 0px hsl(var(--huesat) 10%)'
shadow-elevation-16dp_-_box-shadow: '0px 0px 0px 0px hsl(var(--huesat) 25%)'
# Switches
paper-toggle-button-checked-button-color: 'hsl(var(--base-hue), 90%, 50%)'
paper-toggle-button-checked-bar-color: 'hsl(var(--huesat) 25%)'
paper-toggle-button-unchecked-button-color: 'hsl(var(--huesat) 25%)'
paper-toggle-button-unchecked-bar-color: 'hsl(var(--huesat) 5%)'
# Sliders
paper-slider-knob-color: 'hsl(var(--base-hue), 90%, 50%)'
paper-slider-knob-start-color: 'hsl(var(--base-hue), 80%, 25%)'
paper-slider-pin-color: 'hsl(var(--base-hue), 90%, 50%)'
paper-slider-active-color: 'hsl(var(--base-hue), 90%, 50%)'
paper-slider-container-color: 'hsl(var(--huesat) 28%)'
paper-slider-secondary-color: 'hsl(var(--huesat) 90%)'
paper-slider-disabled-active-color: 'hsl(var(--base-hue), 80%, 25%)'
paper-slider-disabled-secondary-color: 'hsl(var(--base-hue), 80%, 25%)'
paper-dialog-color: 'hsl(var(--base-hue), 20%, 80%)'