So you would need to create 2 x functions. One for archives:
add_filter( 'option_generate_blog_settings', 'dmitry_custom_sketches_archive_settings' );
function dmitry_custom_sketches_archive_settings( $options ) {
if ( is_category( 'sketches' ) ) {
// Add your options ehre
}
return $options;
}
and one for single posts:
add_filter( 'option_generate_blog_settings', 'dmitry_custom_sketches_single_post_settings' );
function dmitry_custom_sketches_single_post_settings( $options ) {
if ( in_category( 'sketches' ) ) {
// Add your options ehre
}
return $options;
}
Note each of the functions has a different name. And they have a slightly different conditional tag ie.
Archives = is_category( 'sketches' )
Singles = in_category( 'sketches' )
More info on WordPress Condtionalm Tags