I tried paying attention to the shading, but it's not going well at all.
Literal
Shadow [to-に] be-careful tried [explanatory-のですが] easily well-not-go is.
An artist's frustration. 陰影 (shading/shadow) is an art term. ~てみた (tried doing) marks the attempt. のですが combines the explanatory のです with が to set up the disappointing result. なかなか with a negative means 'not easily' or 'not at all' despite effort.