Full Idea
'Roses are red; therefore, roses are colored' may be necessarily truth-preserving, but it would not be classified as logically valid by standard systems of logic.
Gist of Idea
'Roses are red; therefore, roses are colored' seems truth-preserving, but not valid in a system
Source
Kathrin Koslicki (The Structure of Objects [2008], 9.3.2)
Book Reference
Koslicki,Kathrin: 'The Structure of Objects' [OUP 2008], p.242