10 min read
Color History Questions That Change Your Formula
The nine intake questions that change a color formula, what each one tells you, the red-flag answers, and the strand test for suspected henna or metallic salts.
The Kolora team
The Kolora color desk
Formulation reference for colorists
Mixing ratios, gray coverage math, underlying pigment and toner selection — compiled from manufacturer technical data sheets, with every figure sourced and dated.
11 min read
Underlying Pigment by Level: Toner Selection Chart
The pigment exposed at every level from 5 to 10, which tone neutralizes it, the developer to use, and a decision tree for diagnosing a toner that failed.
The Kolora team
7 min read
Matrix SoColor Mixing Ratio & Processing Time Chart
SoColor, Ultra Blonde, Sync and 10 Minute side by side: ratio, developer and processing time from the Matrix manual, plus a calculator that turns it into grams.
The Kolora team
12 min read
Formulating for Gray Hair by Percentage: The Math
How much natural base to add at 25%, 50%, 75% and 100% gray, why the standard rules contradict each other, and three worked formulas with developer and timing.
The Kolora team
7 min read
Alfaparf Mixing Ratios: Evolution, Platinum & Color Wear
Evolution of the Color, Platinum, Color Wear, Harmonizer and the Gloss Toner: ratio, Oxid'o strength and processing time in one chart, with a gram calculator.
The Kolora team
7 min read
Igora Royal Mixing Ratio & Developer Chart (Schwarzkopf)
Igora Royal's ratio, the 3%–12% developer ladder and how percentage converts to volume, in one chart — with a calculator that turns the ratio into grams.
The Kolora team
6 min read
Redken Shades EQ Mixing Ratio with Processing Solution
How Shades EQ mixes with Processing Solution and why a developer is no substitute, the timing for gray, and a calculator for the grams in a gloss or a full head.
The Kolora team
7 min read
L'Oréal Mixing Ratios: Majirel, INOA & Dia Light Chart
Majirel, INOA and Dia Light in one chart: ratio, oxidant and processing time, the mistakes that ruin a service, and a calculator that converts each ratio to grams.
The Kolora team
7 min read
Goldwell Mixing Ratios: Topchic & Colorance Chart
Topchic and Colorance ratio, lotion percentage and processing time in one chart — including why Goldwell writes one of them backwards — with a gram calculator.
The Kolora team
14 min read
Best AI Hair Color Formula Apps for Stylists (2026)
A working colorist's comparison of Kolora, Tintly, Color Coach, Blendsor and SalonScale — what each one actually formulates, what it costs, and where each falls short.
The Kolora team
8 min read
Wella Mixing Ratios: Color Touch, Koleston & Illumina
Every Wella line's ratio, developer and timing in one chart, with a gram calculator that weighs out color and emulsion — and what changes for gray coverage.
The Kolora team
10 min read
Cherry Cola Hair Color Formula by Starting Level
What cherry cola is in level and tone, the formula from every realistic starting level, the tone family in six professional lines, and why it fades warm.
The Kolora team
11 min read
Hair Color Numbers Explained: Level and Tone by Brand
How to read a shade code in any professional line: what the level digit means, what each tone digit means, and how six major brands each write theirs.
The Kolora team
13 min read
Hair Color Mixing Ratios by Brand: Complete Chart
Mixing ratios, developer volumes and processing times for 15 professional color lines across Wella, L'Oréal, Redken, Matrix, Alfaparf, Schwarzkopf and Goldwell.
The Kolora team