diff --git a/packages/core/engine/defaults.ts b/packages/core/engine/defaults.ts
index 0f18d84..9dfaf3f 100644
--- a/packages/core/engine/defaults.ts
+++ b/packages/core/engine/defaults.ts
@@ -1,8 +1,9 @@
 import { UmbraInput, UmbraSettings } from './types'
 
 export const defaultSettings: UmbraSettings = {
-  readability: 10,
+  power: 0.15,
   iterations: 15,
+  readability: 70,
   insertion: 9,
   shades: [5, 5, 5, 5, 15, 10, 10, 25, 30, 25, 25, 25],
   tints: [5, 10, 10, 10, 15, 15, 25, 15, 15, 15, 15, 25]
diff --git a/packages/core/engine/index.ts b/packages/core/engine/index.ts
index 2534a4b..6af708c 100644
--- a/packages/core/engine/index.ts
+++ b/packages/core/engine/index.ts
@@ -74,6 +74,8 @@ function umbraAdjust(scheme = defaultScheme) {
   const background = colord(scheme.background)
   const foreground = getReadable({
     readability: scheme.settings?.readability || 4,
+    iterations: scheme.settings?.iterations || 15,
+    power: scheme.settings?.power || 15,
     foreground: colord(scheme.foreground),
     background
   })
diff --git a/packages/core/engine/primitives/color.ts b/packages/core/engine/primitives/color.ts
index c745f3c..c7a2036 100644
--- a/packages/core/engine/primitives/color.ts
+++ b/packages/core/engine/primitives/color.ts
@@ -11,12 +11,14 @@ type ColorRawRange = {
   background: string | Colord
   readability?: number
   iterations?: number
+  power?: number
 }
 
 interface IncreaseContrastUntil {
   color: Colord
   contrast?: Colord
   iterations?: number
+  power?: number
   condition: (newColor: Colord, iterations?: number) => boolean
 }
 
@@ -28,7 +30,8 @@ interface MoveAwayFrom {
 
 const stored = {
   readability: defaultSettings.readability || 11,
-  iterations: defaultSettings.iterations || 15
+  iterations: defaultSettings.iterations || 15,
+  power: defaultSettings.power || 15
 }
 
 function apcaContrast(fg: string | Colord, bg: string | Colord) {
@@ -41,15 +44,22 @@ export const getReadability = (fg: string | Colord, bg: string | Colord) => {
   return apcaContrast(fg, bg)
 }
 
-export const getReadable = ({ foreground, background, readability, iterations }: ColorRawRange) => {
+export const getReadable = ({
+  foreground,
+  background,
+  readability,
+  iterations,
+  power
+}: ColorRawRange) => {
   const color = colord(foreground)
   const contrast = colord(background)
   return increaseContrastUntil({
     color,
     contrast,
     iterations: iterations || stored.iterations,
+    power: power || stored.power,
     condition: (c) => {
-      const current = Math.abs(getReadability(c, background))
+      const current = Math.abs(getReadability(c, contrast))
       return current > (readability || stored.readability)
     }
   })
@@ -59,14 +69,15 @@ export function increaseContrastUntil({
   color,
   contrast,
   condition,
-  iterations = 15
+  iterations = 15,
+  power = 15
 }: IncreaseContrastUntil) {
   let newColor = color
   let count = 0
   while (!condition(newColor, count) && count < iterations) {
     count += 1
     newColor = increaseContrast({
-      val: iterations,
+      val: power,
       color: newColor,
       contrast
     })
diff --git a/packages/core/engine/types/index.ts b/packages/core/engine/types/index.ts
index 7dffc39..fc66b71 100644
--- a/packages/core/engine/types/index.ts
+++ b/packages/core/engine/types/index.ts
@@ -42,8 +42,9 @@ export interface UmbraAdjusted {
 }
 
 export interface UmbraSettings {
-  readability?: number
+  power?: number
   iterations?: number
+  readability?: number
   insertion?: number
   aliases?: Alias | true
   shades?: (number | string)[]
diff --git a/packages/playground/src/App.vue b/packages/playground/src/App.vue
index dd61dad..e404934 100644
--- a/packages/playground/src/App.vue
+++ b/packages/playground/src/App.vue
@@ -49,19 +49,11 @@ const accent3 = {
   color: '#e5484d'
 }
 
-const theme = umbra(
-  {
-    background: '#ffffff',
-    foreground: '#ffffff',
-    accents: [royal, accent, radixRed, radixYellow, radixBlue, accent3, radixRed, success, brown],
-    settings: {
-      readability: 2
-    }
-  }
-  // {
-  //   readability: 90
-  // }
-).apply({ alias: true })
+const theme = umbra({
+  background: '#000000',
+  foreground: '#ffffff',
+  accents: [royal, accent, radixRed, radixYellow, radixBlue, accent3, radixRed, success, brown]
+}).apply({})
 
 // const theme = umbra({
 //   foreground: '#ffffff',