Systeme io Questions and Answers (FAQ)
When you are hovering your mouse over the button in the course/membership pages that you create, the mouseover color is shown as blue. At the moment, the available option to change it is to use CSS to change it. (yes, you can add custom HMTL/CSS/JS code under the settings of your funnel)

One simple workaround is to avoid using the darker color for buttons so that the text remains visible when mouseover, although it is not a big deal.
Having said that, this is NOT a critical feature, so don’t be too concerned about it. While the Systeme io team working on the improvement, focus on another important area of your course/membership, especially those related to conversion.