A scale is a starting point. Notes outside it can create tension, surprise, or a smooth connection into a chord tone. Their effect depends on timing and context.
A chromatic scale moves entirely in semitones: twelve equal steps around the octave. A whole-tone scale moves in whole steps: six steps of two semitones each. Equal spacing alone does not make a scale chromatic.
Try approaching a target note from one fret below. Listen to the tension and release. An outside note can be expressive when you place it intentionally.
Pick up your guitar
Find C in C Ionian. On your guitar, approach it from B and then from D♭. Listen to the two different approaches.