Multiple Custom Field Query

Question

that should be fairly simple using Meta_Query parameter of the WP_Query object

you can set the relation and set as many fields as you like:

$args = array(
'meta_query' => array(
        'relation' => 'OR', //realation 
        array(
            'key' => 'color', //first custom field
            'value' => 'blue',
            'compare' => 'NOT LIKE'
        ),
        array(
            'key' => 'price', //second custom field
            'value' => array( 20, 100 ),
            'type' => 'numeric',
            'compare' => 'BETWEEN'
        )
    )
);

$query = new WP_Query( $args );