This dataset contains data and results associated with the manuscript “Synesthesia in children with difficulties in written language learning” by Anahita Basirat and Jean-Michel Hupé (Consciousness and Cognition, doi: 10.1016/j.concog.2020.10295). color.csv: This file contains RGB and hexadecimal codes of the colors used in the consistency tests. summary.csv: This file contains the information about the participants and the results of the consistency test for letters and digits. A1: session 1, test 1 A2: session 1, test 2 B1: session 2, test 1 B2: session 2, test 1 data: This folder contains raw files of the consistency tests for each participant for the first and the second sessions (respectively, file names ended with a and b). In each raw file, lines 2 to 37 correspond to the first test. Selected letters/digits and colors are shown in columns D and C, respectively. Lines 38 to 73 correspond to the second test. Presented letters/digits and selected colors are shown in columns B and C, respectively. figures: This folder contains the illustration of the results for each participant (as in Figure 3 in the paper).