feature request: auto-color native support

[philpennock]

• Ability to set output color on a per row or column or cell basis (including "header").
• Ability to register simple matchers to validate content and choose color accordingly (including cross-cell ref, so "has same foo- prefix as in reference cell to, eg, match machines in same K8S cluster)
• Ability to map color sanely through to the various backend renderers
• Short-circuit color if color unsupported (eg, markdown output)