Things look different when seen in a different light. So look at them in the light of happiness. Don’t confuse good and bad.

[Hace muy diferentes visos una misma cosa si se mira a diferentes luces: mírese por la de la felicidad. No se han de trocar los frenos al bien y al mal.]

Baltasar Gracián y Morales (1601-1658) Spanish Jesuit priest, writer, philosopher

The Art of Worldly Wisdom [Oráculo Manual y Arte de Prudencia], § 224 (1647) [tr. Maurer (1992)]
    (Source)

(Source (Spanish)). Alternate translations:

One and the same thing, hath its good day, and its bad. Examine it on the fairest side. We must not give the contrary reines to good and evil.
[Flesher ed. (1685)]

The same thing looks quite different in another light; look at it therefore on its best side and do not exchange good for evil.
[tr. Jacobs (1892)]

For one and the same thing has very different faces, as seen in different lights; look upon it in its happiest light, and do not get the controls mixed, as to what is good and what is bad.
[tr. Fischer (1937)]